C++ 代码

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
    vector<double> vec;
    double x;
    for(int i = 0; i < 3; ++i)
    {
        cin >> x;
        vec.push_back(x);
    }
    sort(vec.begin(),vec.end(),greater<double>());
    double a = vec[0], b = vec[1], c = vec[2];
    if(a >= b+c) cout << "NAO FORMA TRIANGULO" << endl;
    else
    {
        if(a*a == b*b + c*c) cout << "TRIANGULO RETANGULO" << endl;
        else if(a*a > b*b + c*c) cout << "TRIANGULO OBTUSANGULO" << endl;
        else if(a*a < b*b + c*c) cout << "TRIANGULO ACUTANGULO" << endl;
        if(a == c) cout << "TRIANGULO EQUILATERO" << endl;
        else if(a == b || b == c) cout << "TRIANGULO ISOSCELES" << endl;
    }

    return 0;
}