oj.uz

Submission #918390

# Submission time Handle Problem Language Result Execution time Memory
918390 2024-01-29T18:55:21 Z divad XOR Sum (info1cup17_xorsum) C++14
11 / 100
 923 ms 15392 KB 
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
const int NMAX = 1e6+2;
int n,v[NMAX];

struct FenwickTree {
    int n;
    vector<int> aib;
    FenwickTree(int _n){
        n = _n;
        aib.resize(n+1);
    }
    void update(int pos, int val){
        pos++;
        for(int i = pos; i <= n; i += (i&-i)){
            aib[i] += val;
        }
    }
    int query(int pos){
        pos++;
        if(pos <= 0){
            return 0;
        }
        int ans = 0;
        for(int i = pos; i > 0; i -= (i&-i)){
            ans += aib[i];
        }
        return ans;
    }
    int query(int l, int r){
        return query(r) - query(l-1);
    }
};

int brut(int k){
    int ans = 0;
    int mod = (1<<(k+1));
    int l = (1<<k), r = (1<<(k+1))-1;
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= i; j++){
            int sum = (v[i]+v[j])%mod;
            int bt = (sum>>k)&1;
            if(bt){
                assert(l <= sum && sum <= r);
            }
            ans += bt;
        }
    }
    return ans;
}

bool inauntru(int x, pii interv){
    auto [l, r] = interv;
    return (l <= x && x <= r);
}

int cnt(int k){
    FenwickTree aib((1<<(k+1)));
    int mod = (1<<(k+1));
    int ans = 0;
    for(int i = 1; i <= n; i++){
        int val = v[i]%mod;
        aib.update(val, 1);
        int l = (1<<k), r = (1<<(k+1))-1;
        l = (l-val+mod)%mod;
        r = (r-val+mod)%mod;
        if(l <= r){
            ans += aib.query(l, r);
        }else{
            ans += aib.query(0, r);
            ans += aib.query(l, mod-1);
        }
    }
    return ans;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> v[i];
    }
    int ans = 0;
    for(int i = 0; i < 20; i++){
        ans += (cnt(i)&1)*(1<<i);
    }
    cout << ans;
    return 0;
}

Compilation message

xorsum.cpp: In function 'bool inauntru(int, pii)':
xorsum.cpp:54:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   54 |     auto [l, r] = interv;
      |          ^

Subtask #1
0 / 7.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 4552 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 923 ms 8708 KB Output is correct
2 Correct 879 ms 12660 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 923 ms 8708 KB Output is correct
2 Correct 879 ms 12660 KB Output is correct
3 Correct 810 ms 15392 KB Output is correct
4 Incorrect 792 ms 14888 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #4
0 / 38.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 4552 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 23.0

# Verdict Execution time Memory Grader output
1 Incorrect 6 ms 4552 KB Output isn't correct
2 Halted 0 ms 0 KB -