Algorithm: Binary Search

Find a specify element target

int binarySearch(int[] nums, int target) {
    int left = 0; 
    int right = nums.length - 1; // right js `nums.length - 1`

    while(left <= right) { // Terminate while loop when left is larger than right.
        int mid = left + (right - left) / 2;
        if(nums[mid] == target)
            return mid; 
        else if (nums[mid] < target)
            left = mid + 1;
        else if (nums[mid] > target)
            right = mid - 1;
    }
    return -1;
}