Java Basic Programming : Exercises, Practice, Solution
Java Basic Exercises [150 exercises with solution]
[An editor is available at the bottom of the page to write and execute the scripts.]
1. Write a Java program to print 'Hello' on screen and then print your name on a separate line. Go to the editor
Expected Output :
Hello
Alexandra Abramov
2. Write a Java program to print the sum of two numbers. Go to the editor
Test Data:
74 + 36
Expected Output :
110
3. Write a Java program to divide two numbers and print on the screen. Go to the editor
Test Data :
50/3
Expected Output :
16
4. Write a Java program to print the result of the following operations. Go to the editor
Test Data:
a. -5 + 8 * 6
b. (55+9) % 9
c. 20 + -3*5 / 8
d. 5 + 15 / 3 * 2 - 8 % 3
Expected Output :
43
1
19
13
5. Write a Java program that takes two numbers as input and display the product of two numbers. Go to the editor
Test Data:
Input first number: 25
Input second number: 5
Expected Output :
25 x 5 = 125
6. Write a Java program to print the sum (addition), multiply, subtract, divide and remainder of two numbers. Go to the editor
Test Data:
Input first number: 125
Input second number: 24
Expected Output :
125 + 24 = 149
125 - 24 = 101
125 x 24 = 3000
125 / 24 = 5
125 mod 24 = 5
7. Write a Java program that takes a number as input and prints its multiplication table upto 10. Go to the editor
Test Data:
Input a number: 8
Expected Output :
8 x 1 = 8
8 x 2 = 16
8 x 3 = 24
...
8 x 10 = 80
8. Write a Java program to display the following pattern. Go to the editor
Sample Pattern :
J a v v a J a a v v a a J J aaaaa V V aaaaa JJ a a V a a
9. Write a Java program to compute the specified expressions and print the output. Go to the editor
Test Data:
((25.5 * 3.5 - 3.5 * 3.5) / (40.5 - 4.5))
Expected Output
2.138888888888889
10. Write a Java program to compute a specified formula. Go to the editor
Specified Formula :
4.0 * (1 - (1.0/3) + (1.0/5) - (1.0/7) + (1.0/9) - (1.0/11))
Expected Output
2.9760461760461765
11. Write a Java program to print the area and perimeter of a circle. Go to the editor
Test Data:
Radius = 7.5
Expected Output
Perimeter is = 47.12388980384689
Area is = 176.71458676442586
12. Write a Java program that takes three numbers as input to calculate and print the average of the numbers. Go to the editor
Click me to see the solution
13. Write a Java program to print the area and perimeter of a rectangle. Go to the editor
Test Data:
Width = 5.5
Height = 8.5
Expected Output
Area is 5.6 * 8.5 = 47.60
Perimeter is 2 * (5.6 + 8.5) = 28.20
14. Write a Java program to print an American flag on the screen. Go to the editor
Expected Output
* * * * * * ================================== * * * * * ================================== * * * * * * ================================== * * * * * ================================== * * * * * * ================================== * * * * * ================================== * * * * * * ================================== * * * * * ================================== * * * * * * ================================== ============================================== ============================================== ============================================== ============================================== ============================================== ==============================================
15. Write a Java program to swap two variables. Go to the editor
Click me to see the solution
16. Write a Java program to print a face. Go to the editor
Expected Output
+"""""+ [| o o |] | ^ | | '-' | +-----+
17. Write a Java program to add two binary numbers. Go to the editor
Input Data:
Input first binary number: 10
Input second binary number: 11
Expected Output
Sum of two binary numbers: 101
18. Write a Java program to multiply two binary numbers. Go to the editor
Input Data:
Input the first binary number: 10
Input the second binary number: 11
Expected Output
Product of two binary numbers: 110
19. Write a Java program to convert a decimal number to binary number. Go to the editor
Input Data:
Input a Decimal Number : 5
Expected Output
Binary number is: 101
20. Write a Java program to convert a decimal number to hexadecimal number. Go to the editor
Input Data:
Input a decimal number: 15
Expected Output
Hexadecimal number is : F
21. Write a Java program to convert a decimal number to octal number. Go to the editor
Input Data:
Input a Decimal Number: 15
Expected Output
Octal number is: 17
22. Write a Java program to convert a binary number to decimal number. Go to the editor
Input Data:
Input a binary number: 100
Expected Output
Decimal Number: 4
23. Write a Java program to convert a binary number to hexadecimal number. Go to the editor
Input Data:
Input a Binary Number: 1101
Expected Output
HexaDecimal value: D
24. Write a Java program to convert a binary number to a Octal number. Go to the editor
Input Data:
Input a Binary Number: 111
Expected Output
Octal number: 7
25. Write a Java program to convert a octal number to a decimal number. Go to the editor
Input Data:
Input any octal number: 10
Expected Output
Equivalent decimal number: 8
26. Write a Java program to convert a octal number to a binary number. Go to the editor
Input Data:
Input any octal number: 7
Expected Output
Equivalent binary number: 111
27. Write a Java program to convert a octal number to a hexadecimal number. Go to the editor
Input Data:
Input a octal number : 100
Expected Output
Equivalent hexadecimal number: 40
28. Write a Java program to convert a hexadecimal to a decimal number. Go to the editor
Input Data:
Input a hexadecimal number: 25
Expected Output
Equivalent decimal number is: 37
29. Write a Java program to convert a hexadecimal to a binary number. Go to the editor
Input Data:
Enter Hexadecimal Number : 37
Expected Output
Equivalent Binary Number is: 110111
30. Write a Java program to convert a hexadecimal to a octal number. Go to the editor
Input Data:
Input a hexadecimal number: 40
Expected Output
Equivalent of octal number is: 100
31. Write a Java program to check whether Java is installed on your computer. Go to the editor
Expected Output
Java Version: 1.8.0_71 Java Runtime Version: 1.8.0_71-b15 Java Home: /opt/jdk/jdk1.8.0_71/jre Java Vendor: Oracle Corporation Java Vendor URL: http://Java.oracle.com/ Java Class Path: .
32. Write a Java program to compare two numbers. Go to the editor
Input Data:
Input first integer: 25
Input second integer: 39
Expected Output
25 != 39 25 < 39 25 <= 39
33. Write a Java program and compute the sum of the digits of an integer. Go to the editor
Input Data:
Input an integer: 25
Expected Output
The sum of the digits is: 7
34. Write a Java program to compute the area of a hexagon. Go to the editor
Area of a hexagon = (6 * s^2)/(4*tan(π/6))
where s is the length of a side
Input Data:
Input the length of a side of the hexagon: 6
Expected Output
The area of the hexagon is: 93.53074360871938
35. Write a Java program to compute the area of a polygon. Go to the editor
Area of a polygon = (n*s^2)/(4*tan(π/n))
where n is n-sided polygon and s is the length of a side
Input Data:
Input the number of sides on the polygon: 7
Input the length of one of the sides: 6
Expected Output
The area is: 130.82084798405722
36. Write a Java program to compute the distance between two points on the surface of earth. Go to the editor
Distance between the two points [ (x1,y1) & (x2,y2)]
d = radius * arccos(sin(x1) * sin(x2) + cos(x1) * cos(x2) * cos(y1 - y2))
Radius of the earth r = 6371.01 Kilometers
Input Data:
Input the latitude of coordinate 1: 25
Input the longitude of coordinate 1: 35
Input the latitude of coordinate 2: 35.5
Input the longitude of coordinate 2: 25.5
Expected Output
The distance between those points is: 1480.0848451069087 km
37. Write a Java program to reverse a string. Go to the editor
Input Data:
Input a string: The quick brown fox
Expected Output
Reverse string: xof nworb kciuq ehT
38. Write a Java program to count the letters, spaces, numbers and other characters of an input string. Go to the editor
Expected Output
The string is : Aa kiu, I swd skieo 236587. GH kiu: sieo?? 25.33 letter: 23 space: 9 number: 10 other: 6
39. Write a Java program to create and display unique three-digit number using 1, 2, 3, 4. Also count how many three-digit numbers are there. Go to the editor
Expected Output
123
124
...
431
432
Total number of the three-digit-number is 24
40. Write a Java program to list the available character sets in charset objects. Go to the editor
Expected Output
List of available character sets:
Big5
Big5-HKSCS
CESU-8
EUC-JP
EUC-KR
GB18030
GB2312
GBK
...
x-SJIS_0213
x-UTF-16LE-BOM
X-UTF-32BE-BOM
X-UTF-32LE-BOM
x-windows-50220
x-windows-50221
x-windows-874
x-windows-949
x-windows-950
x-windows-iso2022jp
41. Write a Java program to print the ascii value of a given character. Go to the editor
Expected Output
The ASCII value of Z is :90
42. Write a Java program to input and display your password. Go to the editor
Expected Output
Input your Password: Your password was: [email protected]
43. Write a Java program to print the following string in a specific format (see the output). Go to the editor
Sample Output
Twinkle, twinkle, little star, How I wonder what you are! Up above the world so high, Like a diamond in the sky. Twinkle, twinkle, little star, How I wonder what you are
44. Write a Java program that accepts an integer (n) and computes the value of n+nn+nnn. Go to the editor
Sample Output:
Input number: 5 5 + 55 + 555
45. Write a Java program to find the size of a specified file. Go to the editor
Sample Output:
/home/students/abc.txt : 0 bytes /home/students/test.txt : 0 bytes
46. Write a Java program to display the system time. Go to the editor
Sample Output:
Current Date time: Fri Jun 16 14:17:40 IST 2017
47. Write a Java program to display the current date time in specific format. Go to the editor
Sample Output:
Now: 2017/06/16 08:52:03.066
48. Write a Java program to print the odd numbers from 1 to 99. Prints one number per line. Go to the editor
Sample Output:
1
3
5
7
9
11
....
91
93
95
97
99
49. Write a Java program to accept a number and check the number is even or not. Prints 1 if the number is even or 0 if the number is odd. Go to the editor
Sample Output:
Input a number: 20 1
50. Write a Java program to print numbers between 1 to 100 which are divisible by 3, 5 and by both. Go to the editor
Sample Output:
Divided by 3:
3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57
, 60, 63, 66, 69, 72, 75, 78, 81, 84, 87, 90, 93, 96, 99,
Divided by 5:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90,
95,
Divided by 3 & 5:
15, 30, 45, 60, 75, 90,
51. Write a Java program to convert a string to an integer in Java. Go to the editor
Sample Output:
Input a number(string): 25 The integer value is: 25
52. Write a Java program to calculate the sum of two integers and return true if the sum is equal to a third integer. Go to the editor
Sample Output:
Input the first number : 5 Input the second number: 10 Input the third number : 15 The result is: true
53. Write a Java program that accepts three integers from the user and return true if the second number is greater than first number and third number is greater than second number. If "abc" is true second number does not need to be greater than first number. Go to the editor
Sample Output:
Input the first number : 5 Input the second number: 10 Input the third number : 15 The result is: true
54. Write a Java program that accepts three integers from the user and return true if two or more of them (integers ) have the same rightmost digit. The integers are non-negative. Go to the editor
Sample Output:
Input the first number : 5 Input the second number: 10 Input the third number : 15 The result is: true
55. Write a Java program to convert seconds to hour, minute and seconds. Go to the editor
Sample Output:
Input seconds: 86399 23:59:59
56. Write a Java program to find the number of values in a given range divisible by a given value. Go to the editor
For example x = 5, y=20 and p =3, find the number of integers within the range x..y and that are divisible by p i.e. { i :x ≤ i ≤ y, i mod p = 0 }
Sample Output:
5
57. Write a Java program to accepts an integer and count the factors of the number. Go to the editor
Sample Output:
Input an integer: 25 3
58. Write a Java program to capitalize the first letter of each word in a sentence. Go to the editor
Sample Output:
Input a Sentence: the quick brown fox jumps over the lazy dog. The Quick Brown Fox Jumps Over The Lazy Dog.
59. Write a Java program to convert a given string into lowercase. Go to the editor
Sample Output:
Input a String: THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG. the quick brown fox jumps over the lazy dog.
60. Write a Java program to find the penultimate (next to last) word of a sentence. Go to the editor
Sample Output:
Input a String: The quick brown fox jumps over the lazy dog. Penultimate word: lazy
61. Write a Java program to reverse a word. Go to the editor
Sample Output:
Input a word: dsaf Reverse word: fasd
62. Write a Java program that accepts three integer values and return true if one of them is 20 or more and less than the substractions of others. Go to the editor
Sample Output:
Input the first number : 15 Input the second number: 20 Input the third number : 25 false
63. Write a Java program that accepts two integer values from the user and return the larger values. However if the two values are the same, return 0 and return the smaller value if the two values have the same remainder when divided by 6. Go to the editor
Sample Output:
Input the first number : 12 Input the second number: 13 Result: 13
64. Write a Java program that accepts two integer values between 25 to 75 and return true if there is a common digit in both numbers. Go to the editor
Sample Output:
Input the first number : 35 Input the second number: 45 Result: true
65. Write a Java program to calculate the modules of two numbers without using any inbuilt modulus operator. Go to the editor
Sample Output:
Input the first number : 19 Input the second number: 7 5
66. Write a Java program to compute the sum of the first 100 prime numbers. Go to the editor
Sample Output:
Sum of the first 100 prime numbers: 24133
67. Write a Java program to insert a word in the middle of the another string. Go to the editor
Insert "Tutorial" in the middle of "Python 3.0", so result will be Python Tutorial 3.0
Sample Output:
Python Tutorial 3.0
68. Write a Java program to create a new string of 4 copies of the last 3 characters of the original string. The length of the original string must be 3 and above. Go to the editor
Sample Output:
3.03.03.03.0
69. Write a Java program to extract the first half of a string of even length. Go to the editor
Test Data: Python
Sample Output:
Pyt
70. Write a Java program to create a string in the form short_string + long_string + short_string from two strings. The strings must not have the same length. Go to the editor
Test Data: Str1 = Python
Str2 = Tutorial
Sample Output:
PythonTutorialPython
71. Write a Java program to create the concatenation of the two strings except removing the first character of each string. The length of the strings must be 1 and above. Go to the editor
Test Data: Str1 = Python
Str2 = Tutorial
Sample Output:
ythonutorial
72. Write a Java program to create a new string taking first three characters from a given string. If the length of the given string is less than 3 use "#" as substitute characters. Go to the editor
Test Data: Str1 = " "
Sample Output:
###
73. Write a Java program to create a new string taking first and last characters from two given strings. If the length of either string is 0 use "#" for missing character. Go to the editor
Test Data: str1 = "Python"
str2 = " "
Sample Output:
P#
74. Write a Java program to test if 10 appears as either the first or last element of an array of integers. The length of the array must be greater than or equal to 2. Go to the editor
Sample Output:
Test Data: array = 10, -20, 0, 30, 40, 60, 10
true
75. Write a Java program to test if the first and the last element of an array of integers are same. The length of the array must be greater than or equal to 2. Go to the editor
Test Data: array = 50, -20, 0, 30, 40, 60, 10
Sample Output:
false
76. Write a Java program to test if the first or the last element of two array of integers are same. The length of the array must be greater than or equal to 2. Go to the editor
Test Data: array1 = 50, -20, 0, 30, 40, 60, 12
array2 = 45, 20, 10, 20, 30, 50, 11
Sample Output:
false
77. Write a Java program to create a new array of length 2 from two arrays of integers with three elements and the new array will contain the first and last elements from the two arrays. Go to the editor
Test Data: array1 = 50, -20, 0
array2 = 5, -50, 10
Sample Output:
Array1: [50, -20, 0] Array2: [5, -50, 10] New Array: [50, 10]
78. Write a Java program to test that a given array of integers of length 2 contains a 4 or a 7. Go to the editor
Sample Output:
Original Array: [5, 7] true
79. Write a Java program to rotate an array (length 3) of integers in left direction. Go to the editor
Sample Output:
Original Array: [20, 30, 40] Rotated Array: [30, 40, 20]
80. Write a Java program to get the larger value between first and last element of an array (length 3) of integers . Go to the editor
Sample Output:
Original Array: [20, 30, 40] Larger value between first and last element: 40
81. Write a Java program to swap the first and last elements of an array (length must be at least 1) and create a new array. Go to the editor
Sample Output:
Original Array: [20, 30, 40] New array after swaping the first and last elements: [40, 30, 20]
82. Write a Java program to find the largest element between first, last, and middle values from an array of integers (even length). Go to the editor
Sample Output:
Original Array: [20, 30, 40, 50, 67] Largest element between first, last, and middle values: 67
83. Write a Java program to multiply corresponding elements of two arrays of integers. Go to the editor
Sample Output:
Array1: [1, 3, -5, 4]
Array2: [1, 4, -5, -2]
Result: 1 12 25 -8
84. Write a Java program to take the last three characters from a given string and add the three characters at both the front and back of the string. String length must be greater than three and more. Go to the editor
Test data: "Python" will be "honPythonhon"
Sample Output:
honPythonhon
85. Write a Java program to check if a string starts with a specified word. Go to the editor
Sample Data: string1 = "Hello how are you?"
Sample Output:
true
86. Write a Java program start with an integer n, divide n by 2 if n is even or multiply by 3 and add 1 if n is odd, repeat the process until n = 1. Go to the editor
87. Write a Java program than read an integer and calculate the sum of its digits and write the number of each digit of the sum in English. Go to the editor
88. Write a Java program to get the current system environment and system properties. Go to the editor
Click me to see the solution
89. Write a Java program to check whether a security manager has already been established for the current application or not. Go to the editor
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90. Write a Java program to get the value of the environment variable PATH, TEMP, USERNAME. Go to the editor
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91. Write a Java program to measure how long some code takes to execute in nanoseconds. Go to the editor
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92. Write a Java program to count the number of even and odd elements in a given array of integers. Go to the editor
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93. Write a Java program to test if an array of integers contains an element 10 next to 10 or an element 20 next to 20, but not both. Go to the editor
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94. Write a Java program to rearrange all the elements of a given array of integers so that all the odd numbers come before all the even numbers. Go to the editor
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95. Write a Java program to create an array (length # 0) of string values. The elements will contain "0", "1", "2" … through ... n-1. Go to the editor
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96. Write a Java program to check if there is a 10 in a given array of integers with a 20 somewhere later in the array. Go to the editor
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97. Write a Java program to check if an array of integers contains a specified number next to each other or there are two same specified numbers separated by one element. Go to the editor
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98. Write a Java program to check if the value 20 appears three times and no 20's are next to each other in a given array of integers. Go to the editor
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99. Write a Java program to check if a specified number appears in every pair of adjacent element of a given array of integers. Go to the editor
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100. Write a Java program to count the two elements of two given arrays of integers with same length, differ by 1 or less. Go to the editor
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101. Write a Java program to check if the number of 10 is greater than number to 20 in a given array of integers. Go to the editor
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102. Write a Java program to check if a specified array of integers contains 10 or 30. Go to the editor
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103. Write a Java program to create a new array from a given array of integers, new array will contain the elements from the given array after the last element value 10. Go to the editor
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104. Write a Java program to create a new array from a given array of integers, new array will contain the elements from the given array before the last element value 10. Go to the editor
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105. Write a Java program to check if a group of numbers (l) at the start and end of a given array are same. Go to the editor
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106. Write a Java program to create a new array that is left shifted from a given array of integers. Go to the editor
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107. Write a Java program to check if an array of integers contains three increasing adjacent numbers. Go to the editor
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108. Write a Java program to add all the digits of a given positive integer until the result has a single digit. Go to the editor
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109. Write a Java program to form a staircase shape of n coins where every k-th row must have exactly k coins. Go to the editor
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110. Write a Java program to check whether a given integer is a power of 4 or not. Go to the editor
Given num = 64, return true. Given num = 6, return false.
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111. Write a Java program to add two numbers without using any arithmetic operators. Go to the editor
Given x = 10 and y = 12; result = 22
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112. Write a Java program to compute the number of trailing zeros in a factorial. Go to the editor
7! = 5040, therefore the output should be 1
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113. Write a Java program to merge two given sorted array of integers and create a new sorted array. Go to the editor
array1 = [1,2,3,4]
array2 = [2,5,7, 8]
result = [1,2,2,3,4,5,7,8]
Click me to see the solution
114. Write a Java program to given a string and an offset, rotate string by offset (rotate from left to right). Go to the editor
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115. Write a Java program to check if a positive number is a palindrome or not. Go to the editor
Input a positive integer: 151
Is 151 is a palindrome number?
true
Click me to see the solution
116. Write a Java program which iterates the integers from 1 to 100. For multiples of three print "Fizz" instead of the number and print "Buzz" for the multiples of five. When number is divided by both three and five, print "fizz buzz". Go to the editor
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117. Write a Java program to compute the square root of a given integer. Go to the editor
Input a positive integer: 25
Square root of 25 is: 5
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118. Write a Java program to get the first occurrence (Position starts from 0.) of a string within a given string. Go to the editor
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119. Write a Java program to get the first occurrence (Position starts from 0.) of an element of a given array. Go to the editor
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120. Write a Java program that searches a value in an m x n matrix. Go to the editor
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121. Write a Java program to reverse a given linked list. Go to the editor
Example: For linked list 20->40->60->80, the reversed linked list is 80->60->40->20
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122. Write a Java program to find a contiguous subarray with largest sum from a given array of integers. Go to the editor
Note: In computer science, the maximum subarray problem is the task of finding the contiguous subarray within a one-dimensional array of numbers which has the largest sum. For example, for the sequence of values −2, 1, −3, 4, −1, 2, 1, −5, 4; the contiguous subarray with the largest sum is 4, −1, 2, 1, with sum 6.
The subarray should contain one integer at least. Click me to see the solution
123. Write a Java program to find the subarray with smallest sum from a given array of integers. Go to the editor
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124. Write a Java program to find the index of a value in a sorted array. If the value does not find return the index where it would be if it were inserted in order. Go to the editor
Example:
[1, 2, 4, 5, 6] 5(target) -> 3(index)
[1, 2, 4, 5, 6] 0(target) -> 0(index)
[1, 2, 4, 5, 6] 7(target) -> 5(index)
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125. Write a Java program to get the preorder traversal of its nodes' values of a given a binary tree. Go to the editor
Example:
10 / \ 20 30 / \ 40 50Expected output: 10 20 40 50 30
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126. Write a Java program to get the inorder traversal of its nodes' values of a given a binary tree. Go to the editor
10 / \ 20 30 / \ 40 50Example:{10, 20, 30, 40, 50}
Output: 40 20 50 10 30
Click me to see the solution
127. Write a Java program to get the Postorder traversal of its nodes' values of a given a binary tree. Go to the editor
10 / \ 20 30 / \ 40 50Click me to see the solution
128.Write a Java program to calculate the median of a given unsorted array of integers. Go to the editor
Original array: [10, 2, 38, 22, 38, 23]
Median of the said array of integers: 30
Original array: [10, 2, 38, 23, 38, 23, 21]
Median of the said array of integers: 23
Click me to see the solution
129. Write a Java program to find a number that appears only once in a given array of integers, all numbers occur twice. Go to the editor
Source Array : [10, 20, 10, 20, 30, 40, 40, 30, 50]
50 appears only once
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130. Write a Java program to find the maximum depth of a given a binary tree. Go to the editor
Sample Output:
The Maximum depth of the binary tree is: 3
Click me to see the solution
131. Write a Java program to find the new length of a given sorted array where each element appear only once (remove the duplicates ). Go to the editor
Original array: [1, 1, 2, 3, 3, 3, 4, 5, 6, 7, 7]
The length of the original array is: 11
After removing duplicates, the new length of the array is: 7
Click me to see the solution
132. Write a Java program to find the new length of a given sorted array where duplicate elements appeared at most twice. Go to the editor
Original array: [1, 1, 2, 3, 3, 3, 4, 5, 6, 7, 7, 7, 7]
The length of the original array is: 13
After removing duplicates, the new length of the array is: 10
Click me to see the solution
133. Write a Java program to find a path from top left to bottom in right direction which minimizes the sum of all numbers along its path. Go to the editor
Note: Move either down or right at any point in time.
Sample Output: Sum of all numbers along its path: 13
Click me to see the solution
134. Write a Java program to find the distinct ways you can climb to the top (n steps to reach to the top) of stairs. Each time you can either climb 1 or 2 steps. Go to the editor
Example: n = 5
a) 1+1+1+1+1 = 5 b) 1+1+1+2 = 5 c) 1+2+2 = 5 d) 2+2+1 = 5 e) 2+1+1+1 = 5 f) 2+1+2 = 5 g) 1+2+1+1 = 5 h) 1+1+2+1 = 5
Sample Output: Distinct ways can you climb to the top: 8
Click me to see the solution
135. Write a Java program to remove duplicates from a sorted linked list. Go to the editor
Original List with duplicate elements:
12->12->13->14->15->15->16->17->17
After removing duplicates from the said list:
12->13->14->15->16->17
Click me to see the solution
136. Write a Java program to find possible unique paths from top-left corner to bottom-right corner of a given grid (m x n). Go to the editor
Note: You can move either down or right at any point in time.
Sample Output: Unique paths from top-left corner to bottom-right corner of the said grid: 3
Click me to see the solution
137. Write a Java program to find possible unique paths considering some obstacles, from top-left corner to bottom-right corner of a given grid (m x n). Go to the editor
Note: You can move either down or right at any point in time and an obstacle and empty space is marked as 1 and 0 respectively in the grid.
Sample grid:
int[][] obstacle_Grid ={
{0, 0, 0},
{0, 1, 0},
{0, 0, 0},
};
Sample Output: Unique paths from top-left corner to bottom-right corner of the said grid (considering some obstacles): 2
Click me to see the solution
138. Write a Java program to find all of the longest word in a given dictionary. Go to the editor
Example-1:
{
"cat",
"flag",
"green",
"country",
"w3resource"
}
Result: "w3resource"
Example-2:
{
"cat",
"dog",
"red",
"is",
"am"
}
Result: "cat", "dog", "red"
Click me to see the solution
139. Write a Java program to get the index of the first number and the last number of a subarray where the sum of numbers is zero from a given array of integers. Go to the editor
Original Array : [1, 2, 3, -6, 5, 4]
Index of the subarray of the said array where the sum of numbers is zero: [0, 3]
Click me to see the solution
140. Write a Java program to merge all overlapping Intervals from a given a collection of intervals. Go to the editor
Sample Output: 1 6
8 10
15 20
Click me to see the solution
141. Write a Java program to check if a given string has all unique characters. Go to the editor
Sample Output: Original String : xyyz
String has all unique characters: false
Click me to see the solution
142. Write a Java program to check if two given strings are anagrams or not. Go to the editor
According to Wikipedia "An anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. For example, the word anagram can be rearranged into nag a ram, or the word binary into brainy."
Sample Output: String-1 : wxyz
String-2 : zyxw
Check if two given strings are anagrams or not?: true
Click me to see the solution
143. Write a Java program to merge two given sorted lists. Go to the editor
Sample Output:
Merge Two Sorted ListsT:
1 2 3 7 9 13 40
Click me to see the solution
144. Write a Java program to remove all occurrences of a specified value in a given array of integers and return the new length of the array. Go to the editor
Sample Output:
Original array: [1, 4, 6, 7, 6, 2]
The length of the new array is: 4
Click me to see the solution
145. Write a Java program to remove the nth element from the end of a given list. Go to the editor
Sample Output:
Original node:
1 2 3 4 5
After removing 2nd element from end:
1 2 3 5
Click me to see the solution
146. Write a Java program to convert an sorted array to binary search tree. Maintain minimal height of the tree. Go to the editor
Sample Output:
2
1
4
6
5
3
Click me to see the solution
147. Write a Java program to find the number of bits required to flip to convert two given integers. Go to the editor
Sample Output:
2
Click me to see the solution
148. Write a Java program to find the index of the first unique character in a given string, assume that there is at least one unique character in the string. Go to the editor
Sample Output:
Original String: wresource
First unique character of the above: 0
Click me to see the solution
149. Write a Java program to check if a given string is a permutation of another given string. Go to the editor
Sample Output:
Original strings: xxyz yxzx
true
Click me to see the solution
150. Write a Java program to test if a binary tree is a subtree of another binary tree. Go to the editor
Sample Output:
Original strings: xxyz yxzx
true
Click me to see the solution
Java Code Editor:
More to Come !
Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.
Java: Tips of the Day
Java: How does the Java 'for each' loop work?
for (Iterator<String> i = someIterable.iterator(); i.hasNext();) {
String item = i.next();
System.out.println(item);
}
Note that if you need to use i.remove(); in your loop, or access the actual iterator in some way, you cannot use the for ( : ) idiom, since the actual iterator is merely inferred.
As was noted by Denis Bueno, this code works for any object that implements the Iterable interface.
Also, if the right-hand side of the for (:) idiom is an array rather than an Iterable object, the internal code uses an int index counter and checks against array.length instead. See the Java Language Specification.
Ref: https://bit.ly/2Z1RtSb
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