// Binary search approach
var mySqrt = function(x) {
    let left = 1;
    let right = x;
    // The square root of 0 or 1 is itself
    if(x < 2) return x;

    // Use binary search to find the square root or the whole number closest to the square root
    while(left < right) {
        // Find the mid point between left and right
        const mid = Math.floor((left + right) / 2)
        // Return the mid point if this is the square root
        if(mid*mid === x) return mid
        // If mid squared is greater than x then the answer must be on the left half of mid
        else if(mid*mid >x) right = mid
        // If mid squred is less than x then the answer must be on the right half of mid
        else left = mid+1
    }
    return left - 1
};