C++ String: Exercises, Practice, Solution

C++ String [42 exercises with solution]

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1. Write a C++ program to reverse a given string.
Example:
Sample Input: w3resource
Sample Output: ecruoser3w
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2. Write a C++ program to change every letter in a given string with the letter following it in the alphabet (i.e. a becomes b, p becomes q, z becomes a).
Example:
Sample Input: w3resource
Sample Output: x3sftpvsdf
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3. Write a C++ program to capitalize the first letter of each word in a given string. Words must be separated by only one space.
Example:
Sample Input: cpp string exercises
Sample Output: Cpp String Exercises
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4. Write a C++ program to find the largest word in a given string.
Example:
Sample Input: C++ is a general-purpose programming language.
Sample Output: programming
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5. Write a C++ program to sort characters (numbers and punctuation symbols are not included) in a string.
Example:
Sample Input: python
Sample Output: hnopty
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6. Write a C++ program to check whether the characters e and g are separated by exactly 2 places anywhere in a given string at least once.
+ Example:
Sample Input: eagerer
Sample Output: eagerer -> 1
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7. Write a C++ program to count all the vowels in a given string.
Example:
Sample Input: eagerer
Sample output: number of vowels -> 4
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8. Write a C++ program to count all the words in a given string.
Example:
Sample Input: Python
Sample Output: number of words -> 1
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9. Write a C++ program to check whether two characters appear equally in a given string.
Example:
Sample Input: aabcdeef
Sample Output: True
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10. Write a C++ program to check if a given string is a Palindrome or not.
A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam, racecar.
Example:
Sample Input: madam
Sample Output: True
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11. Write a C++ program to find a word in a given string that has the highest number of repeated letters.
Example:
Sample Input: Print a welcome text in a separate line.
Sample Output: Word which has the highest number of repeated letters. separate
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12. Write a C++ program to insert a dash character (-) between two odd numbers in a given string of numbers.
Example:
Sample Input: 1345789
Sample Output: Result-> 1-345-789
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13. Write a C++ program to change the case (lower to upper and upper to lower cases) of each character in a given string.
Example:
Sample Input: Pythpn
Sample Output: pYTHON
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14. Write a C++ program to find the numbers in a given string and calculate the sum of all numbers.
Example:
Sample Input: w3resource from 2008
Sample Output: Sum of the numbers: 2011
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15. Write a C++ program to convert a given non-negative integer into English words.
Example:
Sample Input: 12
Sample Output: Twelve
Sample Input: 29
Sample Output: Twenty Nine
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16. Write a C++ program to find the longest common prefix from a given array of strings.
Example:
The longest common prefix is: Pa
The longest common prefix is: J
The longest common prefix is:
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17. Write a C++ program to find all combinations of well-formed brackets from a given pair of parentheses.
Example:
n = 2
[[]] [][]
n = 3
[[]] [][] [[[]]] [[][]] [[]][] [][[]] [][][]
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18. Write a C++ program to find the length of the longest valid (correct-formed) parentheses substring of a given string.
Example:
Original Parentheses string: [[]
Length of longest parentheses: 2
Original Parentheses string: [[]]]
Length of longest parentheses: 4
Original Parentheses string: ]]]][[[[
Length of longest parentheses: 0
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19. Write a C++ program to reverse only the vowels of a given string.
A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant.
Example:
Original string: w3resource
After reversing the vowels of the said string: w3resuorce
Original string: Python
After reversing the vowels of the said string: Python
Original string: Hello
After reversing the vowels of the said string: Holle
Original string: USA
After reversing the vowels of the said string: ASU
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20. Write a C++ program to find the length of the longest palindrome in a given string (uppercase or lowercase letters).
Original string: adcdcdy
Length of the longest palindrome of the said string: 5
Original string: aaa
Length of the longest palindrome of the said string: 3
Original string: aa
Length of the longest palindrome of the said string: 2
Original string: abddddeeff
Length of the longest palindrome of the said string: 4
Original string: PYTHON
Length of the longest palindrome of the said string: 1
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21. Write a C++ program to check whether a given string is a subsequence of another given string. Return 1 for true and 0 for false.
Example:
word1: apple
subse1: apl
Is subse1 is the subsequence of word1? 1
word2: apple
subse2: ppe
Is subse2 is the subsequence of word2? 1
word3: ACGGTGTCGTGCTATGCTGATGCTGACTTATATGCTA
subse3: CGTTCGGCTATGCTTCTACTTATTCTA
Is subse3 is the subsequence of word3? 1
word4: CGTTCGGCTATCGTACGTTCTATTCTATGATTTCTAA
subse4: CGTTCGGCTATGCZTTCTACTTATTCTA
Is subse4 is the subsequence of word4? 0
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22. Write a C++ program to remove all special characters from a given string.
Example:
Original string: abcd $ js# @acde$
New string after removing the special characters from the said string:
abcd js acde
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23. Write a C++ program that counts the number of unique characters in two given strings.
Example:
Original Strings:
String1: Python
String2: Java
Total number of unique characters of the said two strings: 9
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24. Write a C++ program to count the number of duplicate characters in a given string.
Example:
Original String:
Total number of unique characters of the said two strings.
Number of duplicate characters in the said string: 36
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25. Write a C++ program to find the longest sequence of consecutive ones in a given binary string.
Example:
Original Binary String:
1100110001
Longest sequence of consecutive ones of the said binary string:
11
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26. Write a C++ program to check if a given string is a title-cased string or not. When the string is title cased, return "True", otherwise return "False".
Example:
Original String:
The Quick Brown Fox.
Check the said string is a title cased string or not!
True
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27. Write a C++ program to insert a space when a lower character follows an upper character in a given string.
Example:
Original String:
TheQuickBrownFox.
Insert white spaces between lower and uppercase Letters in the said string:
The Quick Brown Fox.
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28. Write a C++ program to extract the first specified number of vowels from a given string. If the specified number is less than the number of vowels present in the text, display "n is less than the number of vowels present in the string".
Example:
Input a string: Input a number:
Extract the first n number of vowels from the said string:
n is less than number of vowels present in the string!
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29. Write a C++ program to print a given integer with commas separating the thousands.
Example:
Input a number:
Print the said integer with commas as thousands separators:
5,000
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30. Write a C++ program to identify the missing letter in a given string (list of alphabets). The method returns, "There is no missing letter!" if no letters are missing from the string.
Example:
Original string: abcdef
Identify the missing letter in the said string:
There is no missing letter!
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31. Write a C++ program to check if a given string contains only uppercase or only lowercase letters. Return "True" if the string is uppercase or lowercase, otherwise "False".
Example:
Original string: ABCDEF
Check whether the said string is uppercase or lowercase: True
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32. Write a C++ program that takes a string and reverses the words of three or more lengths in a string. Return the updated string. As input characters, only spaces and letters are permitted.
Example:
Original string: The quick brown fox jumps over the lazy dog
Reverse the words of three or more lengths of the said string:
ehT kciuq nworb xof spmuj revo eht yzal god
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33. A string is created using the letters of another string. Letters are case sensitive. Write a C++ program to verify that the letters in the second string appear in the first string. Return true otherwise false.
Test Data:
("CPP", "Cpp") -> false
("Java", "Ja") -> true
("Check first string", "sifC") ->true
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34. Write a C++ program that removes a specific word from a given string. Return the updated string.
Test Data:
("Exercises Practice Solution", "Solution") -> "Exercises Practice"
("Exercises Practice Solution", "Practice ") -> "Exercises Solution"
("Exercises Practice Solution", " Solution") -> " Practice Solution"
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35. Write a C++ program to reverse all words that have odd lengths in a string.
Test Data:
("Exercises Practice Solution" ) -> "sesicrexE Practice Solution"
("The quick brown fox jumps over the lazy dog") -> "ehT kciuq nworb xof spmuj over eht lazy dog."
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36. Write a C++ program to check whether there are two consecutive (following each other continuously), identical letters in a given string.
Test Data:
("Exercises") -> 0
("Yellow") -> 1
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37. Write a C++ program that counts the number of instances of a certain character in a given string.
Test Data:
("Exercises", "e") -> 2
("Compilation Time", "i") -> 3
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38. Write a C++ program that removes a specific character from a given string. Return the updated string.
Test Data:
("Filename", "e") -> "Filnam"
("Compilation Time", "i") -> "Complaton Tme"
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39. Write a C++ program that checks whether a given string contains unique characters or not. Return true if the string contains unique characters otherwise false.
Test Data:
("Filename") -> 0
("abc") -> 1
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40. For two given strings, str1 and str2, write a C++ program to select only the characters that are lowercase in the other string at the same position. Return characters as a single string.
Test Data:
("Java", "jscript") -> "scr"
("jScript", "Java") -> "Jva"
("cpp", "c++") -> "c++"
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41. Write a C++ program that finds the position of the second occurrence of a string in another string. If the substring does not appear at least twice return -1.
Test Data:
("the qu qu", "qu") -> 7
("theququ", "qu") -> 5
("thequ", "qu") -> -1
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42. Write a C++ program that alternates the case of each letter in a given string of letters.
Pattern: First lowercase letter then uppercase letter and so on.
Test Data:
("JavaScript") -> "jAvAsCrIpT"
("Python") -> "pYtHoN"
("C++") -> "c++"
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