bool isPerfectSquare(int num) {
if(num==1) return true;
if(num==2) return false;
long head=2,tail=num-1;
while(head<=tail){
long mid=(head+tail)/2;
long t =mid*mid;
if(t<(long)num){
head=mid+1;
}else if(t >(long)num){
tail=mid-1;
}else{
return true;
}
}
return false;
}结果：
标签：平方,return,head,long,有效,tail,num,367 From： https://www.cnblogs.com/llllmz/p/18035010