代码见下

#include<iostream>
#include<cstdio>
#include<iomanip>
#include<cmath>
#include<bitset>
#include<algorithm>
#include<set>
#include<map>
#include<vector>
#include<queue>
#include<stack>
#include<cstring>
#include<string>
using namespace std;
long long a[1000];
int main(){
	for(long long i=0;i<3;i++){
		cin>>a[i];
	}
	sort(a,a+3);
	if(a[0]+a[1]>a[2]){
		if(a[0]*a[0]+a[1]*a[1]>a[2]*a[2]){
			cout<<"Right triangle"<<endl;
			if(a[0]*a[0]+a[1]*a[1]<a[2]*a[2]){
				cout<<"Acute triangle"<<endl;
				if(a[0]==a[1]||a[0]==a[2]||a[1]==a[2]){
					cout<<"Isosceles triangle"<<endl;
					if(a[0]==a[1]&&a[1]==a[2]){
						cout<<"Equilateral triangle"<<endl;
					}
				}
			}
		}
	}
	else{
		cout<<"Not triangle"<<endl;
	}
}