Single Number

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package cn.edu.xidian.sselab.hashtable;

/**
 *
 * @author zhiyong wang
 * title: Single Number
 * content:
 * 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 {

    //利用异或操作，相同为0，相异为1，这样一次循环就能找到不同的那个数
    public int singleNumber(int[] nums){
        int length = nums.length;
        int result = 0;
        for(int i=0;i<length;i++){
            result = result ^ nums[i];
        }
        return result;
    }
    
    public static void main(String[] args) {
        SingleNumber single = new SingleNumber();
        System.out.println(single.singleNumber(new int[]{1,2,1}));;
    }
}