#include<stdio.h>
int main()
{
    int a[4],m,n,b;
    printf("请输入4个不相等的数\n");
    scanf("%d%d%d%d", a[0],a[1],a[2],a[3]);
        for (n = 1; n <= 3; ++n)
        {
            m = 0;
                for (; m <= 2; ++m)
                {
                    if (a[m] > a[m + 1])
                    {
                        b = a[m];
                    a[m] = a[m+1];
                    a[m + 1] = b;
                    }
                }
        }
        printf("\n%d,%d,%d,%d", a[0], a[1], a[2], a[3]);
}

输入加&

#include<stdio.h>
int main()
{
    int a[4],m,n,b;
    printf("请输入4个不相等的数\n");
    scanf("%d%d%d%d", &a[0],&a[1],&a[2],&a[3]);
        for (n = 1; n <= 3; ++n)
        {
            m = 0;
                for (; m <= 2; ++m)
                {
                    if (a[m] > a[m + 1])
                    {
                        b = a[m];
                    a[m] = a[m+1];
                    a[m + 1] = b;
                    }
                }
        }
        printf("\n%d,%d,%d,%d", a[0], a[1], a[2], a[3]);
}

问问题前真的认真思考过了吗？