Submission #169595

#	Time	Username	Problem	Language	Result	Execution time	Memory
169595		Rouge_Hugo	XOR Sum (info1cup17_xorsum)	C++14	11 / 100	1661 ms	10968 KiB

xorsum

#include <bits/stdc++.h>
#define ll long long
#define fast ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);

using namespace std;
int a[1000009];
int n,x,xo;
int main()
{
    cin>>n;
    int mx=0;
    for(int i=0;i<n;i++)
    {
        cin>>x;
        a[x]++;
        mx=max(mx,x);
    }
    for(int i=1;i<=mx;i++)
    {
        if (a[i]==0)continue;
        for(int j=1;j<i;j++)
        {
            if (a[j]==0)continue;
            if ((a[i]*a[j])%2==0)continue;
            xo^=(i+j);
        }
        ll y=a[i]+1;
        y*=a[i];
        y/=2;
        if(y%2)xo^=i*2;
    }
    cout<<xo;
}

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