37 lines
918 B
Java
37 lines
918 B
Java
package com.thinker.bishi.beiyou;
|
|
|
|
import java.util.Scanner;
|
|
|
|
/**
|
|
* @author lzh
|
|
* http://code.bupt.edu.cn/problem/p/84/
|
|
*/
|
|
public class SingleNumber {
|
|
|
|
private static int result(int[] arr,int len){
|
|
int check = 0;
|
|
int chongfu = 0;
|
|
// find chongfu
|
|
for(int i=0;i<len;i++){
|
|
int val = arr[i];
|
|
if((check & (1<<val)) != 0){
|
|
chongfu |= (1<<val);
|
|
}
|
|
check |= (1<<val);
|
|
}
|
|
chongfu = check & (~chongfu);
|
|
return chongfu;
|
|
}
|
|
public static void main(String[] args) {
|
|
Scanner in = new Scanner(System.in);
|
|
int num = Integer.parseInt(in.nextLine());
|
|
String[] numStr = (in.nextLine()).split(" ");
|
|
int[] nums = new int[num];
|
|
for(int i=0;i<num;i++){
|
|
nums[i] = Integer.parseInt(numStr[i]);
|
|
}
|
|
System.out.println(result(nums,num));
|
|
|
|
}
|
|
}
|