ThreeNumberSum

using System;
using System.Collections.Generic;

public class Program {
	public static List<int[]> ThreeNumberSum(int[] array, int targetSum) {
		// Write your code here.
        Array.Sort(array);        
        int num1,front_ptr,end_ptr;
        int lastptr = array.Length -1;
        List<int[]> result = new List<int[]>();
        for(int ctr = 0 ; ctr < array.Length - 2; ctr++)
        {
            num1 = array[ctr];
            front_ptr = ctr+1;
            end_ptr = lastptr;
            while(front_ptr < end_ptr)
            {
                if(num1 + array[front_ptr] + array[end_ptr] == targetSum)
                {
                result.Add(new int[]{num1,array[front_ptr],array[end_ptr]});
                front_ptr++;
                end_ptr--;
                }
                else if(num1 + array[front_ptr] + array[end_ptr] > targetSum)
                    end_ptr--;
                else
                    front_ptr++;
            }
            
        }
		return result;
	}
}