【Medium】69. Sqrt(x)

Implement int sqrt(int x).

Compute and return the square root of x.

中心思想：

二分查找 sqrt(x) < x/2

class Solution { public: int mySqrt(int x) { <span style="white-space:pre"> </span>double begin = 0; double end = x; double result = 1; double mid = 1; while(abs(result-x) > 0.000001){ mid = (begin+end)/2; result = mid*mid; if(result > x) // 二分的范围 end = mid; else begin = mid; } return (int)mid; } };