Math Number Theory Combinatorics
Learner Level

Implement the integerSquareRootFloor method that returns the floor value of the square root of an integer.

The input contains a non-negative integer n. Your task is to return the floor value of its square root.

The floor square root is the largest integer x such that x * x is less than or equal to n. For example, the square root of 17 is a little more than 4, so the answer is 4.

Example 1
Input:
n (int) = 17
Return:
(int) 4
Example 2
Input:
n (int) = 4
Return:
(int) 2
Example 3
Input:
n (int) = 8
Return:
(int) 2

Use binary search between 0 and n to find the largest number whose square is not greater than n.

For each middle value, compare middle * middle with n. If the square is valid, store it as a possible answer and search to the right for a bigger valid value.

If the square is too large, search to the left.

Pseudocode:

function integerSquareRootFloor(n):
    left = 0
    right = n
    answer = 0
    while left <= right:
        mid = left + (right - left) / 2
        square = mid * mid
        if square <= n:
            answer = mid
            left = mid + 1
        else:
            right = mid - 1
    return answer
Run your code to see the result.