[binary search - simple] 69 Square root of X

subject
Example 1：

Input ：x = 4
Output ：2

Example 2：

Input ：x = 8
Output ：2
explain ：8 The arithmetic square root of is 2.82842…, Because the return type is an integer , The decimal part will be removed .

Tips ：

0 <= x <= 231 - 1

【 Code 】
Execution time ：44 ms, In all Python3 Defeated in submission 57.03% Users of
Memory consumption ：15 MB, In all Python3 Defeated in submission 15.94% Users of
Pass the test case ：1017 / 1017

class Solution:
    def mySqrt(self, x: int) -> int:
        left,right=0,x
        while left<=right:
            mid=left+(right-left)//2
            if mid*mid==x:
                return mid
            elif mid*mid<x:
                left=mid+1
            else:
                right=mid-1
        return right

【 Method 2】
Execution time ：36 ms, In all Python3 Defeated in submission 90.57% Users of
Memory consumption ：14.8 MB, In all Python3 Defeated in submission 78.58% Users of
Pass the test case ：1017 / 1017

class Solution:
    def mySqrt(self, x: int) -> int:
        left,right,ans=0,x,-1
        while left<=right:
            mid=left+(right-left)//2
            if mid*mid<=x:
                ans=mid
                left=mid+1
            else:
                right=mid-1
        return ans

【 Method 3】 Newton's iteration
Execution time ：36 ms, In all Python3 Defeated in submission 90.57% Users of
Memory consumption ：15 MB, In all Python3 Defeated in submission 18.06% Users of
Pass the test case ：1017 / 1017

class Solution:
    def mySqrt(self, x: int) -> int:
        left,right=0,x
        def cal(n):
            res=(n+x/n)/2
            if res==n:
                return n
            else:
                return cal(res)
        if x==0:return x
        return int(cal(x))

【 Method 4： Newton's iteration 】
Execution time ：44 ms, In all Python3 Defeated in submission 57.03% Users of
Memory consumption ：14.8 MB, In all Python3 Defeated in submission 84.44% Users of
Pass the test case ：1017 / 1017

class Solution:
    def mySqrt(self, x: int) -> int:
        if x==0:return 0
        cur=x
        while True:
            temp=(cur+x/cur)/2
            if cur-temp<1e-7:
                break
            cur=temp
        return int(cur)