oj.uz

Submission #798357

# Submission time Handle Problem Language Result Execution time Memory
798357 2023-07-30T15:57:54 Z GrindMachine XOR Sum (info1cup17_xorsum) C++17
100 / 100
 1279 ms 21600 KB 
// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    int n; cin >> n;
    vector<int> a(n);
    rep(i,n) cin >> a[i];

    int mx = *max_element(all(a));
    vector<int> b(n);

    auto get = [&](int l, int r){
        return upper_bound(all(b),r) - lower_bound(all(b),l);
    };

    int ans = 0;

    vector<int> cnt(1<<20);

    for(int f = 1; f <= 2*mx; f <<= 1){
        if((f<<1) <= (1<<20)){
            rep(i,f<<1){
                cnt[i] = 0;
            }

            rep(i,n){
                int v = a[i]%(f<<1);
                cnt[v]++;
            }

            int ptr = 0;
            rep(i,f<<1){
                int c = cnt[i];
                rep(j,c){
                    b[ptr++] = i;
                }
            }
        }
        else{ 
            rep(i,n) b[i] = a[i]%(f<<1);
            sort(all(b));
        }
        
        int ptr1 = n-1, ptr2 = n-1, ptr3 = n-1;

        ll cnt1 = 0, cnt2 = 0;
    
        rep(i,n){
            int x = b[i];
            while(ptr1 >= 0 and x+b[ptr1] >= f){
                ptr1--;
            }
            while(ptr2 >= 0 and x+b[ptr2] >= (f<<1)){
                ptr2--;
            }
            while(ptr3 >= 0 and x+b[ptr3] >= 3*f){
                ptr3--;
            }

            int lx = ptr1+1;
            int rx = ptr2;

            cnt1 += max(rx-lx+1,0);
            cnt1 += n-1-ptr3;

            if((x+x)&f){
                cnt1--;
                cnt2++;
            }
        }

        assert(!(cnt1&1));
        ll cnt = (cnt1>>1)+cnt2;

        ans += (cnt&1)*f;
    }

    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message

xorsum.cpp: In function 'void solve(int)':
xorsum.cpp:71:10: warning: variable 'get' set but not used [-Wunused-but-set-variable]
   71 |     auto get = [&](int l, int r){
      |          ^~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4436 KB Output is correct
2 Correct 8 ms 4436 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 182 ms 12256 KB Output is correct
2 Correct 174 ms 11716 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 182 ms 12256 KB Output is correct
2 Correct 174 ms 11716 KB Output is correct
3 Correct 402 ms 12244 KB Output is correct
4 Correct 386 ms 11968 KB Output is correct

Subtask #4
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4436 KB Output is correct
2 Correct 8 ms 4436 KB Output is correct
3 Correct 126 ms 5200 KB Output is correct
4 Correct 125 ms 5204 KB Output is correct

Subtask #5
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 4436 KB Output is correct
2 Correct 8 ms 4436 KB Output is correct
3 Correct 182 ms 12256 KB Output is correct
4 Correct 174 ms 11716 KB Output is correct
5 Correct 402 ms 12244 KB Output is correct
6 Correct 386 ms 11968 KB Output is correct
7 Correct 126 ms 5200 KB Output is correct
8 Correct 125 ms 5204 KB Output is correct
9 Correct 1263 ms 12248 KB Output is correct
10 Correct 1272 ms 21600 KB Output is correct
11 Correct 1279 ms 21600 KB Output is correct