C Language Problem Questions

#pragma warning (disable:4996)
#include <stdio.h>

int GetGCD (int x, int y); // user function declaration

int main()
{
    declaration of local variables within int x, y, result; //main function
    x = y = -1;
    result = 0;

    When (!(x == 0 & & y == 0)) // If both x and y are 0, exit the while statement; if not, repeat
    {
        printf("Please enter two numbers: ");
        scanf("%d %d", &x, &y);

        result = GetGCD(x, y);

        printf("%d, %d maximum number of pledges = %d\n", x, y, result);

    }

    return 0;
}
int GetGCD(int x, int y) {
    int a, b, c;

    a = (x >= y) ? x : y;

    b = (x >= y) ? y : x;


    while (b != 0)
    {
        c = a % b;
        a = b;
        b = c;
    }

    return a;
}

#pragma warning (disable:4996)
#include <stdio.h>

int GetGCD (int x, int y); // user function declaration

int main()
{
    declaration of regional variables within int result; //main function

    int tmp = 0;
    int num = -1;
    printf("Enter at least two non-negative integers" [Only the number before entering 0 is valid] : ");

    while(1)
    {

        if (tmp == 0)
        {
            scanf("%d", &result);           
            tmp++;
        }
        else
        {
            scanf(" %d", &num);
            tmp++;
        }
        if (num == 0)
            break;

        if (tmp >= 2)
            result = GetGCD(result, num);

    }

    rewind(stdin);
    getchar();
    printf("Maximum number of pledges = %d\n\n", result);

    printf ("Press any key to exit";
    getchar();
    return 0;
}
int GetGCD(int x, int y) {
    int a, b, c;

    a = (x >= y) ? x : y;

    b = (x >= y) ? y : x;

    c = a % b;
    a = b;
    b = c;

    if (c == 0)
        return a;
    else return GetGCD(a, b); call the recursive function until the value of //c becomes 0, and return the maximum number of pledges only when the value of c becomes 0
}