依次判断，顺便点个赞个呗，谢谢！ 
#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&&a==c&&b==c)
                cout<<"Equilateral triangle!"<<endl;
            else if(a!=b&&a!=c&&b!=c)
                cout<<"Ordinary triangle!"<<endl;
            else if(!((a==b&&a==c&&b==c)&&(a!=b&&a!=c&&b!=c)))
                cout<<"Isosceles triangle!"<<endl;
        }
        else
            cout<<"Not a triangle!"<<endl;
    }
    return 0;
}