这道题原以为很简单却不知道哪错了，大佬们看看吧（c++）

#include <bits/stdc++.h>
using namespace std;
int main(){
    int a[4];
    cin>>a[1]>>a[2]>>a[3];
    sort(a+1,a+3+1);
    if(a[1]+a[2]<=a[3]){
        cout<<"Not triangle";
        return 0;
    }
    if(a[1]*a[1]+a[2]*a[2]==a[3]*a[3]) cout<<"Right triangle";
    else if(a[1]*a[1]+a[2]*a[2]>a[3]*a[3]) cout<<"Acute triangle";
    else if(a[1]*a[1]+a[2]*a[2]<a[3]*a[3]) cout<<"Obtuse triangle";
    if(a[1]==a[2] || a[2]==a[3] || a[1]==a[3]) cout<<"Isosceles triangle";
    if(a[1]==a[2] && a[1]==a[3] && a[2]==a[3]) cout<<"Equilateral triangle";
    return 0;
}