class Solution {
public:
bool isPerfectSquare(int num) {
int i=0;
bool flag=0;
while(1){
i++;
if((long long)i*i==num||(long long)(i+1)*(i+1)==num){
return true;
break;
}
if((long long)(i+1)*(i+1)>num) break;
}
if(flag){
return true;
}else{
return false;
}
}
};