Submission #1149307

#	Time	Username	Problem	Language	Result	Execution time	Memory
1149307		arkanefury	XOR Sum (info1cup17_xorsum)	C++20	18 / 100	1693 ms	27892 KiB

xorsum

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define in insert
#define lb lower_bound
#define F first
#define S second
#define sz size()
#define all(v) v.begin(),v.end()
#define FOR1(x, n) for(int j = x; j <= n; j ++)
#define FOR(x, n, m, d) for(int x = n; x <= m; x += d)
#define FORR(x, n, m, d) for(int x = n; x >= m; x -= d)
#define nikita ios_base::sync_with_stdio(0), cin.tie(0);
const int N =  1e6+5;
int a[N], b[N], pref[N], dp[N];
int n,m,k,sum=0,x,y, ans, r, cnt, l, mod = 1e9+7, mt[N];
bool used[N];
vector<int>g[N];
string s, str;
map<int, int>mp;
void solve(){
    nikita
    cin >> n;
    ans = 0;
    vector<int>v;
    int mx = 0;
    FOR(i, 1, n, 1){
        cin >> a[i];
        mx = max(mx, a[i]);
        if(a[i] <= 4e3){
        b[a[i]]++;
        if(b[a[i]] == 1)v.pb(a[i]);
        }
    }
    if(mx > 4e3){
        ans = 0;
    FOR(i, 1, n, 1){
        FOR(j, i, n, 1){
            ans ^= (a[i] + a[j]);
        }
    }
    cout << ans;
    return;
    }
    FOR(i, 0, v.sz-1, 1){
        FOR(j, i, v.sz-1, 1){
            if(v[i] == v[j]){
                if((b[v[i]] * (b[v[i]] - 1) / 2 + b[v[i]]) % 2)ans ^= (v[i] * 2);
                continue;
            }
            if(b[v[i]] * b[v[j]] % 2)ans ^= (v[i] + v[j]);
        }
    }
    cout << ans;
}
signed main(){
    nikita
    int tt = 1;
    if(!tt)cin >> tt;
    FOR(i, 1, tt, 1)solve();
}

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