C# Source Code

// Author: Hannes du Plooy
// Date: 8 October 2013
// Objective: To solve the following
//  ONE
//  ONE
//  ONE
// +ONE
// ----
//  TEN
using System;

namespace Puzzle001App {
    class Puzzle001 {
        static void Main(string[] args) {
	        int O,E,N,T,E2;
	        int carry,tmp;

	        for(O=1;O<10;O++) {
		        for(E=0;E<10;E++) {
		            if (O != E) {
		                tmp = E*4;
		                carry = tmp/10;
		                N = tmp % 10;
		                if (N == O || N == E)
		                    continue;
		                tmp = carry + N*4;
		                carry = tmp/10;
		                E2 = tmp % 10;
		                if (E2 != E)
		                    continue;
		                T = carry + O*4;
		                if (T >= 10)
		                    continue;
		                if (T == O || T == E || T == N)
		                    continue;
		                Console.WriteLine("Answer is \n");
		                Console.WriteLine(" "+O+N+E);
		                Console.WriteLine(" "+O+N+E);
		                Console.WriteLine(" "+O+N+E);
		                Console.WriteLine(" "+O+N+E);
		                Console.WriteLine("----");
		                Console.WriteLine(" " +T+E+N);
		                return;
		            }
		        }
	        }            
        }
    }
}