Submission #922626

#	Time	Username	Problem	Language	Result	Execution time	Memory
922626		HaciyevAlik	XOR Sum (info1cup17_xorsum)	C++14	18 / 100	425 ms	27228 KiB

xorsum

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int mx=4*1000;
int main(){
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int n,x=0; cin >> n;
    int a[n+1];
    unordered_map<int,int> mp;
    for(int i=1;i<=n;++i) {
        cin >> a[i];
        mp[a[i]]++;
    }
    if(n<=mx) {
        for(int i=1;i<=n;++i) {
            for(int j=i;j<=n;++j) {
                x^=(a[i]+a[j]);
            }
        }
        return cout<<x,0;
    }
    for(int i=1;i<=mx;++i) {
        if(!mp[i]) continue;
        if((mp[i]*(mp[i]+1)/2)%2) {
            x^=(i*2);
        }
        for(int j=i+1;j<=mx;++j) {
            if(mp[i]&&mp[j]&&(mp[i]*mp[j]%2==1)) {
                x^=(i+j);
            }
        }
    }  
    cout << x;
    return 0;   
}

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