Tag: reverse order

Lets write a simple C program to print natural numbers from 1 to N in reverse order, using while loop.

Related Read:
while loop in C programming
C Program to Print Natural Numbers from 1 to N using While loop

Source Code: C Program to Print Natural Numbers from 1 to N In Reverse Order using While loop

 
#include < stdio.h >

int main()
{
    int num;

    printf("Enter a positive number\n");
    scanf("%d", &num);

    printf("\nNatural numbers from 1 to %d are:\n", num);

    while(num)
    {
        printf("%d  ", num);
        num--;
    }

    printf("\n");

    return 0;
}

Output 1:
Enter a positive number
10

Natural numbers from 1 to 10 are:
10 9 8 7 6 5 4 3 2 1

Output 2:
Enter a positive number
14

Natural numbers from 1 to 14 are:
14 13 12 11 10 9 8 7 6 5 4 3 2 1

C Program to Print Natural Numbers from 1 to N In Reverse Order using While loop

Logic To Print Natural Numbers from 1 to N In Reverse Order using While loop

We ask the user to enter a positive number, and store it inside a variable num. We iterate through the loop until the number is equal to zero. For example, if user enters num = 5, we iterate the loop 5 times. Inside the while loop we keep decrementing the value of variable num. Once the value of num becomes 0, we exit the loop. For each iteration we print the value of num.

This way we printout all the natural numbers from 1 to N, in reverse order.

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