题解 | 三角形判断

#include <iostream>
using namespace std;

int main() {
    int a,b,c;
    while(cin >> a >> b >> c)
    {
        if(a + b > c && a- b < c)
        {
            if(a == b && b == c) cout << "Equilateral triangle!" << endl; //注意不能a==b==c,因为这不是连续判断，而是将a==b的结果与c做判断，如果a==b，c！=1的话，判断结果就为0，所以就不能输出等边三角形
            else    if(a == b || c == a || b ==c) cout << "Isosceles triangle!" << endl;
            else    cout << "Ordinary triangle!" << endl;
        }
        else cout << "Not a triangle!" << endl;
    }
}
// 64 位输出请用 printf("%lld")