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if...else...的嵌套

#include <iostream>
using namespace std;

int main() {
    int a, b, c;

    while (cin >> a >> b >> c) {
        if ((a + b > c) && (a + c > b) && (b + c > a)) {
            if ((a == b) && (b == c)) {
                cout << "Equilateral triangle!" << endl;
            } else if ((a == b) || (b == c) || (a == c)) {
                cout << "Isosceles triangle!" << endl;
            } else {
                cout << "Ordinary triangle!" << endl;
            }
        } else {
            cout << "Not a triangle!" << endl;
        }
    }

    return 0;
}