Square Root

Problem

Given a non-negative integer x, return the integer part of its square root. For any non-perfect square, round down to the nearest integer.

Examples:

integerSqrt(4);
// 2

integerSqrt(10);
// 3
// The square root of 10 is approximately 3.1622, so round down to the nearest integer

Time Complexity

Aim for a time complexity of O(log n), where n is the input integer x.