oj.uz

Submission #270450

# Submission time Handle Problem Language Result Execution time Memory
270450 2020-08-17T15:46:32 Z Atill83 XOR Sum (info1cup17_xorsum) C++14
77 / 100
 1600 ms 39628 KB 
#include <bits/stdc++.h>
#define ff first
#define ss second
#define endl '\n'
using namespace std;
const long long INF = (long long) 1e18;
const int mod = (int) 1e9+7;
const int MAXN = (int) 1e6+5;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll n;
ll v[MAXN];
pll b[MAXN];
pll nw[MAXN];
ll pw[45];
const ll L = 31;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);cout.tie(nullptr);


    cin>>n;

    for(ll i = 0; i < n; i++){
        cin>>v[i];
        b[i] = {v[i] % 2, i};
    }
    
    sort(b, b + n);

    for(ll i = 0; i <= L; i++){
        pw[i] = (1LL<<i);
    }

    ll ans = 0;

    for(ll i = 0; i < L; i++){
        ll cnt = 0;
        ll r3 = n, r2 = n, r1 = n;

        for(ll j = 0; j < n; j++){
            while(r3 && b[j].ff + b[r3 - 1].ff >= pw[i] + pw[i + 1]) r3--;
            while(r2 && b[j].ff + b[r2 - 1].ff >= pw[i + 1]) r2--;
            while(r1 && b[j].ff + b[r1 - 1].ff >= pw[i]) r1--;
            cnt += n - r1 - (r3 - r2);
        }

        for(ll j = 0; j < n; j++){
            if((2LL*b[j].ff) & pw[i]) cnt++;
        }
        assert(cnt % 2 == 0);
        cnt /= 2;
        if(cnt % 2) ans += pw[i];

        if(i + 1 == L) break;
        ll last = 0;
        for(ll j = 0; j < n; j++){
            if((v[b[j].ss] & pw[i + 1]) == 0){
                nw[last++] = b[j];
            }
        }

        for(ll j = 0; j < n; j++){
            if((v[b[j].ss] & pw[i + 1]) != 0){
                b[j].ff += pw[i + 1];
                nw[last++] = b[j];
            }
        }
        for(ll j = 0; j < n; j++){
            b[j] = nw[j];
            nw[j] = {-1, -1};
        }
        assert(last == n);
    }

    cout<<ans<<endl;


    #ifdef Local
        cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 512 KB Output is correct
2 Correct 6 ms 512 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1389 ms 39628 KB Output is correct
2 Correct 1278 ms 36860 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1389 ms 39628 KB Output is correct
2 Correct 1278 ms 36860 KB Output is correct
3 Correct 1404 ms 39568 KB Output is correct
4 Correct 1372 ms 38136 KB Output is correct

Subtask #4
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 512 KB Output is correct
2 Correct 6 ms 512 KB Output is correct
3 Correct 125 ms 4344 KB Output is correct
4 Correct 127 ms 4224 KB Output is correct

Subtask #5
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 512 KB Output is correct
2 Correct 6 ms 512 KB Output is correct
3 Correct 1389 ms 39628 KB Output is correct
4 Correct 1278 ms 36860 KB Output is correct
5 Correct 1404 ms 39568 KB Output is correct
6 Correct 1372 ms 38136 KB Output is correct
7 Correct 125 ms 4344 KB Output is correct
8 Correct 127 ms 4224 KB Output is correct
9 Execution timed out 1619 ms 39528 KB Time limit exceeded
10 Halted 0 ms 0 KB -