#include "stdio.h"
void main()
{
    int a=0,b=0,c=0;
    printf("请输入三个数字：a，b，c\n");
    scanf("%d%d%d",&a,&b,&c);
    printf("a,b,c三个数字俺大->小输出为:");
    if(a>b)
    {
        if(a>c)
        {
            printf("%d,",a);
            if(b>c)
            {
                printf("%d,",b);
                printf("%d",c);
            }
            else
            {
                printf("%d,",c);
                printf("%d",b);
            }
        }
        else
        {
            printf("%d,",c);
            printf("%d,",a);
            printf("%d",b);
        }
    }
    else
    {
        if(b>c)
        {
            printf("%d,",b);
            if(a>c)
            {
                printf("%d,",a);
                printf("%d",c);
            }
            else
            {
                printf("%d,",c);
                printf("%d",a);
            }
        }
        else
        {
            printf("%d,",c);
            printf("%d,",b);
            printf("%d,",a);
        }
    }
}
跟着程序画就好了

如果谁又更简单的办法通知我啊，我也是个新手