Sansa and XOR

                            Solution in C :

In  C :





#include <stdio.h>
#include <stdlib.h> 
#define MOD 1000000007
#define s(k) scanf("%d",&k);
#define sll(k) scanf("%lld",&k);
#define p(k) printf("%d\n",k);
#define pll(k) printf("%lld\n",k);
#define f(i,N) for(i=0;i<N;i++)
#define f1(i,N) for(i=0;i<=N;i++)
#define f2(i,N) for(i=1;i<=N;i++)
typedef long long ll;
int main(){
    int t,n,k,sum,i;
    s(t)
    while(t--){
        s(n)
        if(!(n%2)){
            printf("0\n");
            f(i,n)
                s(k)
        } else {
            sum=0;
            f(i,n){
                s(k)
                if(!(i%2))
                    sum^=k;
            }
            p(sum);
        }
    }
    return 0;
}
                        

                        Solution in C++ :

In  C++  :






#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <limits>
#include <cstring>
#include <string>
using namespace std;

#define pairii pair<int, int>
#define llong long long
#define pb push_back
#define sortall(x) sort((x).begin(), (x).end())
#define INFI  numeric_limits<int>::max()
#define INFLL numeric_limits<llong>::max()
#define INFD  numeric_limits<double>::max()
#define FOR(i,s,n) for (int (i) = (s); (i) < (n); (i)++)
#define FORZ(i,n) FOR((i),0,(n))

void solve() {
  int n;
  scanf("%d",&n);
  int res = 0;
  FORZ(i,n) {
    int x;
    scanf("%d",&x);
    if ((i+1)%2 && (n-i)%2) {
      res ^= x;
    }
  }
  printf("%d\n",res);
}

int main() {
#ifdef DEBUG
  freopen("in.txt", "r", stdin);
  freopen("out.txt", "w", stdout);
#endif
  int t;
  scanf("%d",&t);
  FORZ(i,t) solve();
  return 0;
}
                    

                        Solution in Java :

In  Java :







import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;

public class Solution {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String line = br.readLine();
		int num = Integer.parseInt(line);
		
		for (int i = 0; i < num; i++) {
			String count = br.readLine();
			String[] ns = br.readLine().split(" ");
			sansaXor(ns, Integer.valueOf(count));
		}

	}
	
	public static void sansaXor(String[] strs, int count){
		Map<Integer,Integer> map = new HashMap<Integer,Integer>();
		long result = 0;
		for(int i = 0; i < count; i++){
			int numCount = (i + 1)*(count - i);
			int tmp = Integer.valueOf(strs[i]);
			if(map.containsKey(tmp)){
				map.put(tmp, numCount+map.get(tmp));
			}else{
				map.put(tmp, numCount);
			}
		}
		
		for(int k: map.keySet()){
			int value = map.get(k);
			if(value%2!=0){
				result = result^k;
			}
		}
		
		System.out.println(result);
	}
}
                    

                        Solution in Python : 
                            
In  Python3 :






for _ in range(int(input())):
    N = int(input())
    A = tuple(map(int,input().split()))
    X = 0
    for i, x in enumerate(A):
        if ((i+1) * (N-i)) % 2 == 1:
            X ^= x
    print(X)