Submission #497018

#	Time	Username	Problem	Language	Result	Execution time	Memory
497018		vinnipuh01	XOR Sum (info1cup17_xorsum)	C++17	18 / 100	1687 ms	4220 KiB

xorsum

#include <iostream>
#include <bits/stdc++.h>
#include <cmath>
#include <algorithm>
#include <vector>
#include <deque>
#include <set>
#include <stack>
#include <string>
#include <map>
#include <queue>
 
using namespace std;
 
const long long oo = 1000000000000000000;
 
long long int  sum, ans = 0, mx = 0, mn = 1000000000, num, pos;
 
 
/*
    ViHHiPuh
 
   (( `'-""``""-'` ))
     )-__-_.._-__-(
   / --- (o _ o) --- \
   \ .-* ( .0. ) *-. /
   _'-. ,_ '=' _, .-'_
  / `;#'#'# - #'#'#;` \
 \_)) -----'#'----- ((_/
      # --------- #
  '# ------- ------ #'
  /..-'# ------- #'-.\
  _\...-\'# -- #'/-.../_
  ((____)- '#' -(____))
 
 
    cout << fixed << setprecision(6) << x;
 
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
 
    freopen ( "sum.in", "r", stdin )
*/
 
int mp[ 10001 ];
map <int, int> mpp;
set <int> st, s;
vector <int> v;
 
int main () {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
	int n;
	cin >> n;
	int a[ n + 1 ];
	for ( int i = 1; i <= n; i ++ ) {
		cin >> a[ i ];
		mx = max( mx, a[ i ] + 0ll );
	}
	if ( mx >= 5000 ) {
		for ( int i = 1; i <= n; i ++ ) {
			for ( int j = i; j <= n; j ++ ) {
				sum = a[ i ] + a[ j ];
				ans = ans ^ ( sum );
			}
		}
	}
	else {
		for ( int i = 1; i <= n; i ++ )
			mp[ a[ i ] ] ++;
		for ( int i = 1; i <= mx; i ++ ) {
			sum = mp[ i ] * ( mp[ i ] + 1 ) / 2;
			if ( sum % 2 )
				ans = ans ^ ( i + i );
			for ( int j = i + 1; j <= mx; j ++ ) {
				sum = mp[ i ] * ( mp[ j ] );
				if ( sum % 2 )
					ans = ans ^ ( i + j );
			}
		}
	}
	cout << ans;
}


/*

4
3 9 6 6

6
3
10
20


1 2 3
4 5 6 = 19

6 5 2
1 4 3 = 15

5 2

*/

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 38
• Subtask 5: 0 / 23