Binary Search

C++

#include <bits/stdc++.h>

// C++ Code

Java

import java.util.*;
import java.io.*;

class BinarySearch {
    static int binarySearch(int[] nums, int target) {
        if (nums == null || nums.length == 0)
            return -1;

        int left = 0, right = nums.length - 1;
        while (left <= right) {

            int mid = left + (right - left) / 2;
            if (nums[mid] == target) {
                return mid;
            } else if (nums[mid] < target) {
                left = mid + 1;
            } else {
                right = mid - 1;
            }
        }

        // left > right
        return -1;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        int target = sc.nextInt();

        int[] arr = new int[n];

        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        Arrays.sort(arr);

        int ans = binarySearch(arr, target);

        System.out.println(ans);

    }
}

Python

def hello_world():
  print 'Hello, world!'