求两个或三个正整数中的最大数，用带有默认参数的函数来实现

#include<iostream>

using namespace std;

int main()

{

int max(int a,int b,int c=0);

int a,b,c;

cout<<"please enter a b c:";

cin>>a>>b>>c;

cout<<"max(a,b,c)="<<max(a,b,c)<<endl;

cout<<"max(a,b)="<<max(a,b)<<endl;

return 0;

}

int max(int a,int b,int c)

{

if(b>a) a=b;

if(c>a) a=c;

return a;

}