Submission #850633

#	Time	Username	Problem	Language	Result	Execution time	Memory
850633		d4xn	A Difficult(y) Choice (BOI21_books)	C++17	0 / 100	1 ms	344 KiB

books

#include <bits/stdc++.h>

#include "books.h"

using namespace std;
//
// --- Sample implementation for the task books ---
//
// To compile this program with the sample grader, place:
//     books.h books_sample.cpp sample_grader.cpp
// in a single folder and run:
//     g++ books_sample.cpp sample_grader.cpp
// in this folder.
//

#define ll long long

const ll N = 1e5+5;

ll dp[N];

ll pw(ll x, ll y) {
  int sum = 0;
  for (int i = 0; i < y; i++) {
    sum += x+i;
  }
  return sum;
}

void solve(int N, int K, long long A, int S) {
    // TODO implement this function
    /*
    if (skim(2) == 42) {
        impossible();
    } else {
        answer({1, 3});
    }
    */

    ll l = 1;
    ll r = N;
    while (l < r) {
      ll mid = (l+r)>>1;
      dp[mid] = skim(mid);
      if (pw(dp[mid], K) >= A) r = mid;
      else l = mid+1;
      //cerr << mid << " " << dp[mid] << " " << K << " " << A << " " << l << " " << r << endl;
    }

    ll x = l;
    for (ll i = 1; i < K; i++) {
      if (x+i <= N) dp[x+i] = skim(x+i);
      if (x-i > 0) dp[x-i] = skim(x-i);
    }

    vector<ll> v;
    for (int i = x-K+1; i <= x+K-1; i++) {
      if (0 < i && i <= N) v.push_back(i);
    }
    ll sz = v.size();

    for (ll mask = 0; mask < (1ll << sz); mask++) {
      if (__builtin_popcount(mask) != K) continue;
      vector<int> ans;
      ll sum = 0;
      for (int i = 0; i < sz; i++) {
        if ((mask >> i) & 1ll) {
          ans.push_back(v[i]);
          sum += dp[v[i]];
        }
      }
      if (A <= sum && sum <= A*2) {
        answer(ans);
        return;
      }
    }
    impossible();
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20