c语言中for循环相关问题

Question

这个分解质因数中,第二个for循环有啥用,j变量的意义在哪

#include<stdio.h>


int main()
{
    int n, i, j, k = 1;
    scanf("%d", &n);
    printf("%d=", n);
    for (i = 2; i <= n; i++)
    {
        for (j = 2; j < i; j++)
            if (i%j == 0) break;
        if (j >= i)
            while (n%i == 0)
            {
                n = n / i;
                if (k == 1) { printf("%d", i); k++; }
                else printf("*%d", i);
            }
    }
    return 0;
}

Answer 1

#include<stdio.h>
 
 
int main()
{
    int n, i, j, k = 1;
    scanf("%d", &n);
    printf("%d=", n);
    for (i = 2; i <= n; i++)
    {
        
            while (n%i == 0)
            {
                n = n / i;
                if (k == 1) { printf("%d", i); k++; }
                else printf("*%d", i);
            }
    }
    return 0;
}