从键盘输入3个数，将最大值放在变量a中，最小值放在变量c中。    例如，输入的数为：55   12   34， 输出结果应当是：a=55.0,b=34.0,c=12.0。
#include<stdio.h>
int mian()
float x;float y;float z;float a;float b;float c;
{
    float k;
    printf("请输入3个数字：\n");
    scanf("%f%f%f,x,y,z");
    {
        if (x>y)
            x=a;
            {
                if (z<y)
            y=b;
        z=c;
        else y=c;
        z=b;
            }
            if(y>x)
                y=a;
            {
                if(z<x)
                    z=c;
                x=b;
                else z=b;
                x=c;
            }
            if (z>y)
                z=a;
            {
                if (x>y)
                    x=b;
                y=c;
                else x=c;
                y=b;
            }
    printf("\n",a,b,c)
    }