// Author: Li Long, [email protected]

// Date: Apr 17, 2014

// Source: http://oj.leetcode.com/problems/single-number/

// Analysis: http://blog.csdn.net/lilong_dream/article/details/19556493

// Given an array of integers, every element appears twice except for one. Find that single one.

// Note:

// Your algorithm should have a linear runtime complexity.

// Could you implement it without using extra memory?

public class SingleNumber {

public int singleNumber(int[] A) {

// Note: The Solution object is instantiated only once and is reused by each test case.

int result = 0;

for(int num : A) {

result ^= num;

}

return result;

}

public static void main(String[] args) {

SingleNumber slt = new SingleNumber();

int[] A = new int[] { 1, 2, 1, 2, 3, 4, 4 };

System.out.println(slt.singleNumber(A));

}

}