##Single Number
Given 2*n + 1 numbers, every numbers occurs twice except one, find it.
Have you met this question in a real interview? Yes
Example
Given [1,2,2,1,3,4,3], return 4
####Challenge One-pass, constant extra space.
####Tags Expand Greedy
####解法
- 异或就可以
public class Solution {
/**
*@param A : an integer array
*return : a integer
*/
public int singleNumber(int[] A) {
if (A.length == 0) {
return 0;
}
int n = A[0];
for(int i = 1; i < A.length; i++) {
n = n ^ A[i];
}
return n;
}
}