输入三个数，输出最大数，最小数
最大最小值
https://ac.nowcoder.com/acm/problem/22015
直接使用fmax()、fmin()函数即可
#include<bits/stdc++.h>
using namespace std;
int main()
{
int a,b,c;
cin>>a>>b>>c;
int max_num=fmax(a,fmax(b,c));
int min_num=fmin(a,fmin(b,c));
cout<<"The maximum number is : "<<max_num<<endl;
cout<<"The minimum number is : "<<min_num<<endl;
}
