为什么while循环打印一行？

Question

I'm trying to print using C:

01010
01010
01010
01010

using nested loops and if only, I created this code:

#include <stdio.h>
void main()
{
    int n = 1, x = 0, count = 1, m = 0;
    while (m <= 5)
    {
        while (n <= 5)
        {
            if (x == 0)
            {
                printf("%d", x);
                x++;
            }
            else if (x == 1)
            {
                printf("%d", x);
                x--;
            }
            n++;
        }
        m++;
    }
}

But the output is 01010 one line only, may I know what's the reason and how should I fix it?

Answer 1

I would do it like that:

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

    for (int i = 0; i < 5; ++i)
    {
        for (int j = 0, x = 0; j < 5; ++j, x=!x)
            printf("%d", x);
        printf("\n");
    }
}

Your problem is that the while loop does not reset n and x . A for loop is better, it always starts with the initialization part before the first iteration. To fix your code add x=0; n=1; x=0; n=1; before while (n <= 5) .

You also did not print a newline, so everything would be in the same line.

Your if (x==0) x++; else if (x==1) x--; if (x==0) x++; else if (x==1) x--; is the same as x =;x;, from 0 to 1 and from 1 to 0 .