# C Basic: Exercises, Practice, Solution

## C Basic Declarations and Expressions [52 exercises with solution]

[*An editor is available at the bottom of the page to write and execute the scripts.*]

**1.** Write a C program to print your name, date of birth. and mobile number. Go to the editor

*Expected Output*:

Name : Alexandra Abramov DOB : July 14, 1975 Mobile : 99-9999999999

**2.** Write a C program to print a block F using hash (#), where the F has a height of six characters and width of five and four characters. Go to the editor

*Expected Output*:

###### # # ##### # # #

**3.** Write a C program to print a big 'C'. Go to the editor

*Expected Output*:

###### ## ## # # # # # ## ## ######

**4.** Write a C program to print the following characters in a reverse way. Go to the editor

*Test Characters*: 'X', 'M', 'L'

*Expected Output*:

The reverse of XML is LMX

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**5.** Write a C program to compute the perimeter and area of a rectangle with a height of 7 inches. and width of 5 inches. Go to the editor

*Expected Output*:

Perimeter of the rectangle = 24 inches

Area of the rectangle = 35 square inches

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**6.** Write a C program to compute the perimeter and area of a circle with a radius of 6 inches. Go to the editor

*Expected Output*:

Perimeter of the Circle = 37.680000 inches

Area of the Circle = 113.040001 square inches

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**7.** Write a C program to display multiple variables. Go to the editor

Sample *Variable*s :

a+ c, x + c,dx + x, ((int) dx) + ax, a + x, s + b, ax + b, s + c, ax + c, ax + ux

*Declaration* :

int a = 125, b = 12345;

long ax = 1234567890;

short s = 4043;

float x = 2.13459;

double dx = 1.1415927;

char c = 'W';

unsigned long ux = 2541567890;

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**8.** Write a C program to convert specified days into years, weeks and days. Go to the editor

Note: Ignore leap year.

Test Data :

Number of days : 1329

Expected Output :

Years: 3

Weeks: 33

Days: 3

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**9.** Write a C program that accepts two integers from the user and calculate the sum of the two integers. Go to the editor

Test Data :

Input the first integer: 25

Input the second integer: 38

Expected Output:

Sum of the above two integers = 63

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**10.** Write a C program that accepts two integers from the user and calculate the product of the two integers. Go to the editor

Test Data :

Input the first integer: 25

Input the second integer: 15

Expected Output:

Product of the above two integers = 375

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**11.** Write a C program that accepts two item’s weight (floating points' values ) and number of purchase (floating points' values) and calculate the average value of the items. Go to the editor

Test Data :

Weight - Item1: 15

No. of item1: 5

Weight - Item2: 25

No. of item2: 4

Expected Output:

Average Value = 19.444444

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**12.** Write a C program that accepts an employee's ID, total worked hours of a month and the amount he received per hour. Print the employee's ID and salary (with two decimal places) of a particular month. Go to the editor

Test Data :

Input the Employees ID(Max. 10 chars): 0342

Input the working hrs: 8

Salary amount/hr: 15000

Expected Output:

Employees ID = 0342

Salary = U$ 120000.00

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**13.** Write a C program that accepts three integers and find the maximum of three. Go to the editor

Test Data :

Input the first integer: 25

Input the second integer: 35

Input the third integer: 15

Expected Output:

Maximum value of three integers: 35

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**14.** Write a C program to calculate a bike’s average consumption from the given total distance (integer value) traveled (in km) and spent fuel (in liters, float number – 2 decimal point). Go to the editor

Test Data :

Input total distance in km: 350

Input total fuel spent in liters: 5

Expected Output:

Average consumption (km/lt) 70.000

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**15.** Write a C program to calculate the distance between the two points. Go to the editor

Test Data :

Input x1: 25

Input y1: 15

Input x2: 35

Input y2: 10

Expected Output:

Distance between the said points: 11.1803

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**16.** Write a C program to read an amount (integer value) and break the amount into smallest possible number of bank notes. Go to the editor

Test Data :

Input the amount: 375

Expected Output:

There are:

3 Note(s) of 100.00

1 Note(s) of 50.00

1 Note(s) of 20.00

0 Note(s) of 10.00

1 Note(s) of 5.00

0 Note(s) of 2.00

0 Note(s) of 1.00

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**17.** Write a C program to convert a given integer (in seconds) to hours, minutes and seconds. Go to the editor

Test Data :

Input seconds: 25300

Expected Output:

There are:

H:M:S - 7:1:40

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**18.** Write a C program to convert a given integer (in days) to years, months and days, assumes that all months have 30 days and all years have 365 days. Go to the editor

Test Data :

Input no. of days: 2535

Expected Output:

6 Year(s)

11 Month(s)

15 Day(s)

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**19.** Write a C program that accepts 4 integers p, q, r, s from the user where r and s are positive and p is even. If q is greater than r and s is greater than p and if the sum of r and s is greater than the sum of p and q print "Correct values", otherwise print "Wrong values". Go to the editor

Test Data :

Input the second integer: 35

Input the third integer: 15

Input the fourth integer: 46

Expected Output:

Wrong values

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**20.** Write a C program to print the roots of Bhaskara’s formula from the given three floating numbers. Display a message if it is not possible to find the roots. Go to the editor

Test Data :

Input the first number(a): 25

Input the second number(b): 35

Input the third number(c): 12

Expected Output:

Root1 = -0.60000

Root2 = -0.80000

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**21.** Write a C program that reads an integer and check the specified range where it belongs. Print an error message if the number is negative and greater than 80. Go to the editor

Test Data :

Input an intger: 15

Expected Output:

Range [0, 20]

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**22.** Write a C program that read 5 numbers and sum of all odd values between them. Go to the editor

Test Data :

Input the first number: 11

Input the second number: 17

Input the third number: 13

Input the fourth number: 12

Input the fifth number: 5

Expected Output:

Sum of all odd values: 46

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**22.** Write a C program that reads three floating values and check if it is possible to make a triangle with them. Also calculate the perimeter of the triangle if the said values are valid. Go to the editor

Test Data :

Input the first integer: 5

Input the second integer: 15

Input the third integer: 10

Expected Output:

Numbers in sorted order: 5 10 15

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**23.** Write a C program that reads three floating values and check if it is possible to make a triangle with them. Also calculate the perimeter of the triangle if the said values are valid. Go to the editor

Test Data :

Input the first number: 25

Input the second number: 15

Input the third number: 35

Expected Output:

Perimeter = 75.0

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**24.** Write a C program that reads two integers and checks if they are multiplied or not. Go to the editor

Test Data :

Input the first number: 5

Input the second number: 15

Expected Output:

Multiplied!

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**25.** Write a C program that reads an integer between 1 and 12 and print the month of the year in English. Go to the editor

Test Data :

Input a number between 1 to 12 to get the month name: 8

Expected Output:

August

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**26.** Write a C program that prints all even numbers between 1 and 50 (inclusive). Go to the editor

Test Data :

Even numbers between 1 to 50 (inclusive):

Expected Output:

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50

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**27.** Write a C program that read 5 numbers and counts the number of positive numbers and negative numbers. Go to the editor

Test Data :

Input the first number: 5

Input the second number: -4

Input the third number: 10

Input the fourth number: 15

Input the fifth number: -1

Expected Output:

Number of positive numbers: 3

Number of negative numbers: 2

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**28.** Write a C program that read 5 numbers and counts the number of positive numbers and print the average of all positive values. Go to the editor

Test Data :

Input the first number: 5

Input the second number: 8

Input the third number: 10

Input the fourth number: -5

Input the fifth number: 25

Expected Output:

Number of positive numbers: 4

Average value of the said positive numbers: 12.00

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**29.** Write a C program that read 5 numbers and sum of all odd values between them. Go to the editor

Test Data :

Input the first number: 5

Input the second number: 7

Input the third number: 9

Input the fourth number: 10

Input the fifth number: 13

Expected Output:

Sum of all odd values: 34

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**30.** Write a C program to find and print the square of each one of the even values from 1 to a specified value. Go to the editor

Test Data :

List of square of each one of the even values from 1 to a 4 :

Expected Output:

2^2 = 4

4^2 = 16

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**31.** Write a C program to check a given integer is positive even, negative even, positive odd or negative odd. Print even if the number is 0. Go to the editor

Test Data :

Input an integer: 13

Expected Output:

Positive Odd

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**32.** Write a C program to print all numbers between 1 to 100 which divided by a specified number and the remainder will be 3. Go to the editor

Test Data :

Input an integer: 25

Expected Output:

3

28

53

78

103

128

153

178

203

228

253

278

303

328

353

378

403

428

453

478

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**33.** Write a C program that accepts some integers from the user and find the highest value and the input position. Go to the editor

Test Data :

Input 5 integers:

5

7

15

23

45

Expected Output:

Highest value: 45

Position: 5

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**34.** Write a C program to print the numbers from the lowest to the highest (inclusive) and the sum of consecutive integers from a given pair of numbers. Go to the editor

Test Data :

Input a pair of numbers (for example 10,2):

Input first number of the pair: 10

Input second number of the pair: 2

Expected Output:

List of odd numbers: 3

5

7

9

Sum=24

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**35.** Write a C program to check if two numbers in a pair is in ascending order or descending order. Go to the editor

Test Data :

Input a pair of numbers (for example 10,2 : 2,10):

Input first number of the pair: 10

Expected Output:

Input second number of the pair: 2

The pair is in descending order!

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**36.** Write a C program to read a password until it is correct. For wrong password print "Incorrect password" and for correct password print "Correct password" and quit the program. The correct password is 1234. Go to the editor

Test Data :

Input the password: 1234

Expected Output:

Correct password

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**37.** Write a C program to read the coordinates(x, y) (in Cartesian system) and find the quadrant to which it belongs (Quadrant -I, Quadrant -II, Quadrant -III, Quadrant -IV). Go to the editor

Note: A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a pair of numerical coordinates.

These are often numbered from 1st to 4th and denoted by Roman numerals: I (where the signs of the (x,y) coordinates are I(+,+), II (−,+), III (−,−), and IV (+,−).

Test Data :

Input the Coordinate(x,y):

x: 25

y: 15

Expected Output:

Quadrant-I(+,+)

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**38.** Write a program that reads two numbers and divide the first number by second number. If the division not possible print "Division not possible". Go to the editor

Test Data :

Input two numbers:

x: 25

y: 5

Expected Output: 5.0

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**39.** Write a C program to calculate the sum of all number divisible by 17 between two given integer numbers. Go to the editor

Test Data :

Input the first integer: 50
Input the second integer: 99

Expected Output:

Sum: 3521

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**40.** Write a C program to find all numbers which dividing it by 7 and the remainder is equal to 2 or 3 between two given integer numbers. Go to the editor

Test Data :

Input the first integer: 25

Input the second integer: 45

Expected Output:

30

31

37

38

44

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**41.** Write a C program to print 3 numbers in a line, starting from 1 and print n lines. Accept number of lines (n, integer) from the user. Go to the editor

Test Data :

Input number of lines: 5

Expected Output:

1 2 3

4 5 6

7 8 9

10 11 12

13 14 15

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**42.** Write a C program to print a number, it’s square and cube in a line, starting from 1 and print n lines. Accept number of lines (n, integer) from the user. Go to the editor

Test Data :

Input number of lines: 5

Expected Output:

1 1 1

2 4 8

3 9 27

4 16 64

5 25 125

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**43.** Write a C program that reads two integers p and q, print p number of lines in a sequence of 1 to b in a line. Go to the editor

Test Data :

Input number of lines: 5

Number of characters in a line: 6

Expected Output:

1 2 3 4 5 6

7 8 9 10 11 12

13 14 15 16 17 18

19 20 21 22 23 24

25 26 27 28 29 30

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**44.** Write a C program to calculate the average marks of mathematics of some students. Input 0 (excluding to calculate the average) or negative value to terminate the input process. Go to the editor

Test Data :

Input Mathematics marks (0 to terminate): 10

15

20

25

0

Expected Output:

Average marks in Mathematics: 17.50

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**45.** Write a C program to calculate the value of S where S = 1 + 1/2 + 1/3 + … + 1/50. Go to the editor

Expected Output:

Value of S: 4.50

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**46.** Write a C program to calculate the value of S where S = 1 + 3/2 + 5/4 + 7/8. Go to the editor

Expected Output:

Value of series: 4.62

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**47.** Write a C program that reads an integer and find all its divisor. Go to the editor

Test Data:

Input an integer: 45

Expected Output:

All the divisor of 45 are:

1

3

5

9

15

45

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**48.** Write a C program to read and print the elements of an array of length 7, before print replace every negative number, zero with 100. Go to the editor

Test Data:

Input the 5 members of the array:

25

45

35

65

15

Expected Output:

Array values are:

n[0] = 25

n[1] = 45

n[2] = 35

n[3] = 65

n[4] = 15

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**49.** Write a C program to read and print the elements of an array of length 7, before print, put the triple of the previous position starting from the second position of the array. Go to the editor

For example, if the first number is 2, the array numbers must be 2, 6, 18, 54 and 162

Test Data:

Input the first number of the array:
5

Expected Output:

n[0] = 5

n[1] = 15

n[2] = 45

n[3] = 135

n[4] = 405

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**50.** Write a C program to read an array of length 5 and print the position and value of the array elements of value less than 5. Go to the editor

Test Data:

Input the 5 members of the array:

15

25

4

35

40

Expected Output:

A[2] = 4.0

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**51.** Write a C program to read an array of length 6, change the first element by the last, the second element by the fifth and the third element by the fourth. Print the elements of the modified array. Go to the editor

Test Data:

Input the 5 members of the array:

15

20

25

30

35

Expected Output:

array_n[0] = 35

array_n[1] = 30

array_n[2] = 25

array_n[3] = 20

array_n[4] = 15

Click me to see the solution

**52.** Write a C program to read an array of length 6 and find the smallest element and its position. Go to the editor

Test Data:

Input the length of the array: 5
Input the array elements:

25

35

20

14

45

Expected Output:

Smallest Value: 14

Position of the element: 3

Click me to see the solution

## Practice online

#include <stdio.h> int main() { }