[leetcode]69. Sqrt(x)

题目链接：https://leetcode.com/problems/sqrtx/#/description

Implement

int sqrt(int x)

.

Compute and return the square root of x.

class Solution {
public:
int mySqrt(int x) {
if(x==0)
return 0;
int left=1,right=INT32_MAX;
while(true)
{
int mid=left+(right-left)/2;
if(mid>x/mid)
right=mid-1;
else
{
if(mid+1>x/(mid+1))
return mid;
left=mid+1;
}
}
}
};

class Solution {
public:
int mySqrt(int x) {
if(x==0)
return 0;
long long left=1,right=INT32_MAX;
long long mid;
while(true)
{
mid=left+(right-left)/2;
if(mid*mid>x)
right=mid-1;
else
{
if((mid+1)*(mid+1)>x)
return mid;
left=mid+1;
}
}
return mid;
}
};