Question

In this example you are allowed to use from the C standard library only functions for input and output (e.g. printf(), scanf())

Complete the following functions using C programming language:

Complete the int Q7a(intQ7_input) function takes only a seven-digit positive integer as input and returns it reversed. For example, if the integer is 9806593, the program should print 3956089. You are not permitted to use any function of C standard library other than scanf()and printf().You are not permitted to use arrays either. For the case when the integer ends with 0, the number printed cannot have leading 0’s (Eg: input 3412400; output 42143).

Note: Use the division and remainder operators to separate the number into its individual digits.

Answer 1

#include <stdio.h>

// function to calculate reverse of number
int Q7a(int Q7_input){
    // initializing reverse number with 0
    int reverse = 0;
    // repeat until input number is greater than 0
    while(Q7_input > 0){
        // update reverse number each time
        // multiply the current value of reverse with 10
        // and then add it to the last digit of input
        reverse = reverse * 10 + Q7_input % 10;
        // shift the digits of the input one digit right
        Q7_input /= 10;
    }
    // returning the reverse number
    return reverse;
}
int main(){
    int Q7_input;
    scanf("%d", &Q7_input);
    int reverse = Q7a(Q7_input);
    printf("%d", reverse);
    return 0;
}

OUTPUT:-

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