leetcode

Sqrt(x)

Implement int sqrt(int x).

Compute and return the square root of x.

Solution1:

better

  public int mySqrt(int x) {    long r = x;    while (r * r > x) {      r = (r + x / r) / 2;    }    return (int) r;  }

Solution2:

  public int mySqrt(int x) {    if (x == 0)      return 0;    int left = 1, right = Integer.MAX_VALUE;    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;      }    }  }