题目链接:
so easy
Time Limit: 2000/1000 MS (Java/Others)
Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 138 Accepted Submission(s): 110
Problem Description
Given an array with
your task is: calculate xor of all f(s), here s⊆S.
n
integers, assume f(S) as the result of executing xor operation among all the elements of set S. e.g. if S={1,2,3} then f(S)=0.your task is: calculate xor of all f(s), here s⊆S.
Input
This problem has multi test cases. First line contains a single integer T(T≤20) which represents the number of test cases.
For each test case, the first line contains a single integer number n(1≤n≤1,000) that represents the size of the given set. then the following line consists of ndifferent integer numbers indicate elements(≤109) of the given set.
For each test case, the first line contains a single integer number n(1≤n≤1,000) that represents the size of the given set. then the following line consists of ndifferent integer numbers indicate elements(≤109) of the given set.
Output
For each test case, print a single integer as the answer.
Sample Input
1
3
1 2 3
Sample Output
0
In the sample,$S = {1, 2, 3}$, subsets of $S$ are: $varnothing$, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3}
题意:问一个集合的所有子集合的异或和的异或和;
思路:因为a^a=0;所以就看代码;
AC代码:
#include <iostream> #include <cstring> #include <cstdio> #include <algorithm> using namespace std; const long long mod=1e9+7; int main() { int t,n,a[1004]; scanf("%d",&t); while(t--) { scanf("%d",&n); for(int i=1;i<=n;i++) { scanf("%d",&a[i]); } if(n==1) { cout<<a[1]<<" "; } else cout<<"0"<<" "; } return 0; }