C++ 代码
使用现学现卖的sort()对数组从小到大排序
#include<iostream>
#include<algorithm>
#include<iomanip>
using namespace std;
int main(){
float abc[3] = {},a,b,c;
cin>>abc[0]>>abc[1]>>abc[2];
a=abc[0];b=abc[1];c=abc[2];
sort(abc,abc+3,less<float>());
if (abc[0] + abc[1] <= abc[2] || abc[2] - abc[1] >= abc[0])
cout<<fixed<<setprecision(1)<<"Area = "<< (a + b )*c/2;
else{
cout<<"Perimetro = "<< abc[0] +abc[1] + abc[2];
}
}