LeetCode 69. Sqrt(x)

LeetCode 69. Sqrt(x)

int sqrt(int x)

Input: 4
Output: 2

Input: 8
Output: 2
Explanation: The square root of 8 is 2.82842..., and since we want to return an integer, the decimal part will be truncated.

public int mySqrt(int x) {                 //直接使用暴力法找超时，考虑使用二分查找
int left=1;
int right=x;
while(left<=right){
int mid=left+(right-left)/2;
if(mid==x/mid)
return mid;
else if(mid>x/mid)
right=mid-1;
else {
left=mid+1;
}
}
return right;               //举个例子可以得出应该返回right
}