IceCreamParlour.java

package ctci;
//https://www.hackerrank.com/challenges/ctci-ice-cream-parlor
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

class IceCream implements Comparable<IceCream> {
	int flavor;
	int index;

	public IceCream(int flavor, int index) {
		this.flavor = flavor;
		this.index = index;
	}

	@Override
	public int compareTo(IceCream o1) {
		return o1.flavor > this.flavor ? -1 : o1.flavor < this.flavor ? 1 : 0;
	}

	public boolean equals(IceCream o) {
		return o.flavor == this.flavor;
	}
}

public class IceCreamParlour {

	public static int binarySearch(int first, int last, IceCream[] arr, int search) {

		int mid = 0;
		if (first > last)
			return -1;
		else {
			mid = (first + last) / 2;
		}
		if (search == arr[mid].flavor)
			return arr[mid].index;
		else if (search > arr[mid].flavor)
			return binarySearch(mid + 1, last, arr, search);
		else
			return binarySearch(first, mid - 1, arr, search);

	}

	public static void main(String[] args) {

		int t;
		int n, m;

		Scanner in = new Scanner(System.in);
		t = in.nextInt();
		for (int test = 0; test < t; test++) {

			m = in.nextInt();
			n = in.nextInt();
			IceCream[] arr = new IceCream[n];

			for (int i = 0; i < n; i++)
				arr[i] = new IceCream(in.nextInt(), i + 1);

			Arrays.sort(arr);
			int firstIndex = 100000, secondIndex = 100000;
			for (int i = 0; i < n - 1; i++) {
				int search = m - arr[i].flavor;
				if (search >= arr[i].flavor) {
					int index = binarySearch(i + 1, n - 1, arr, search);
					if (index != -1) {
						System.out.println(Math.min(arr[i].index, index) + " " + Math.max(arr[i].index, index));
						break;

					}
				}
			}

		}

	}

}