Submission #496828

#	Time	Username	Problem	Language	Result	Execution time	Memory
496828		ergagan	XOR Sum (info1cup17_xorsum)	C++17	56 / 100	1692 ms	50556 KiB

xorsum

//я так много думал, что опять попал
#include <bits/stdc++.h>
#define all(x) x.begin(),x.end()
#define pb push_back
#define ppb pop_back
#define pf push_front
#define ppf pop_front
#define f first
#define s second
#define left(v) v + v
#define right(v) v + v + 1
#define ub upper_bound
#define lb lower_bound

using namespace std;
typedef long long ll;

#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

//17 SEVENTEEN
const long double Pi = acos(-1.0);
const ll dx[] = {0,0,1,-1};
const ll dy[] = {1,-1,0,0};
const ll N = (ll) 1e6 + 17;
const ll M = (ll) 5e3 + 69;
const ll inf = (ll) 1e14 + 3;
const ll mod = (ll) 1e9 + 7;
ll sq(ll x) { return x * x; }

ll zxc = 1, a[N], cnt[N];

vector<ll> v;
map<ll, ll> mp;

void solve() {
    ll n, xr = 0, mx = 0;
    cin >> n;
    for(ll i = 1; i <= n; i++) {
        cin >> a[i];
        mx = max(mx, a[i]);
        mp[a[i]]++;
    }

    if(mx > M) {

        for(ll i = 1; i <= n; i++) {
            if(!mp[a[i]]) continue;
            if(mp[a[i]] % 2 == 1) v.pb(a[i]);
            if(!(mp[a[i]] % 2)) v.pb(a[i]), v.pb(a[i]);
            mp[a[i]] = 0;
        }

        for(ll i = 0; i < v.size(); i++) {
            for(ll j = i; j < v.size(); j++) {
                xr ^= (v[i] + v[j]);
            }
        }
        cout << xr;
        return;
    }
    if(mx <= M) {
        for(ll i = 1; i <= n; i++) {
            cnt[a[i]]++;
        }

        for(ll i = 1; i <= M; i++) {
            for(ll j = i; j <= M; j++) {
                if(cnt[i] && cnt[j]) {
                    if(i == j && (cnt[i] * (cnt[i] + 1) / 2) % 2) xr ^= (i + j);
                    if(cnt[i] * cnt[j] % 2 && i != j) xr ^= (i + j);
                }
            }
        }
        cout << xr;
        return;
    }

}

int main(/*Уверенно*/) {
ios_base::sync_with_stdio(0);
    cin.tie(0);
/*
	freopen(".in", "r", stdin);
	freopen(".out", "w", stdout);
*/
//    cin >> zxc;
    while(zxc--) {
        solve();
    }
  	return 0;
}
// さよならさ いかなくちゃ

Compilation message (stderr)

xorsum.cpp:18: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
   18 | #pragma comment(linker, "/stack:200000000")
      | 
xorsum.cpp: In function 'void solve()':
xorsum.cpp:55:25: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         for(ll i = 0; i < v.size(); i++) {
      |                       ~~^~~~~~~~~~
xorsum.cpp:56:29: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |             for(ll j = i; j < v.size(); j++) {
      |                           ~~^~~~~~~~~~

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