Single Number

Single Number

问题：

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

思路：

异或

我的方法：

public class Solution {

    public int singleNumber(int[] A) {

        int result = 0 ;

        for(int i = 0 ; i < A.length; i ++)

        {

            result ^= A[i] ;

        }

        return result ;

    }

}

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别人的方法：

public class Solution {

    public int singleNumber(int[] A) {

        if(A == null || A.length == 0) {

            return -1;

        }

        int rst = 0;

        for (int i = 0; i < A.length; i++) {

            rst ^= A[i];

        }

        return rst;

    }

}

View Code

学习之处：

命名用rst比较简练