# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
496765 | Nalrimet | XOR Sum (info1cup17_xorsum) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#pragma GCC optimization("g", on)
#pragma GCC optimize ("inline")
#pragma GCC optimization("03")
#pragma GCC optimization("unroll-loops")
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popused,abm,mmx,avx,tune=native")
using namespace std;
const int N = 1e6 + 5;
const long long inf = 1000000000;
#define ll long long
#define F first
#define S second
#define pb push_back
int n, x[N];
map<int, bool> used;
map<int, int> cnt;
vector<int> v;
long long res, f;
main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for(int i = 1; i <= n; ++i){
cin >> x[i];
used[x[i]] = !used[x[i]];
cnt[x[i]]++;
}
for(int i = 1; i <= n; ++i){
if(cnt[x[i]]) {
f = cnt[x[i]];
if(f * (f - 1) / 2 % 2 == 1) res ^= x[i] + x[i];
cnt[x[i]] = 0;
}
if(used[x[i]]) {
v.pb(x[i]);
used[x[i]] = 0;
}
}
for(int i = 0; i < v.size(); ++i){
for(int j = i; j < v.size(); ++j){
res ^= v[i] + v[j];
}
}
cout << res;
}