Submission #850749

#	Time	Username	Problem	Language	Result	Execution time	Memory
850749		d4xn	A Difficult(y) Choice (BOI21_books)	C++17	0 / 100	1 ms	1300 KiB

books

#include <bits/stdc++.h>
#include "books.h"

using namespace std;

#define ll long long

const ll N = 1e5+5;

ll dp[N];

void solve(int N, int K, long long A, int S) {
    memset(dp, -1, sizeof(dp));

    ll l = 1;
    ll r = N;
    while (l < r) {
      ll mid = (l+r)>>1;
      if (dp[mid] == -1) dp[mid] = skim(mid);
      if (dp[mid] < A) l = mid+1;
      else r = mid;
    }

    vector<int> test;
    test.push_back(l);
    ll cnt = dp[l];
    for (ll i = 1; i <= K-1; i++) {
      if (dp[i] == -1) dp[i] = skim(i);
      cnt += dp[i];
      test.push_back(i);
    }
    if (K-1 < l && A <= cnt && cnt <= A*2) {
      answer(test);
      return;
    }
    
    if (K >= l) {
      impossible();
      return;
    }

    cnt = 0;
    for (ll i = 1; i <= K; i++) {
      if (dp[i] == -1) dp[i] = skim(i);
      cnt += dp[i];
    }
    if (cnt > 2*A) {
      impossible();
      return;
    }

    for (ll i = l-1; i >= l-K; i--) {
      if (dp[i] == -1) dp[i] = skim(i);
    }

    for (ll i = 0; i <= K; i++) {
      cnt = 0;
      vector<int> ans;
      for (ll j = 1; j <= i; j++) {
        cnt += dp[j];
        ans.push_back(j);
      }
      for (ll j = 0; j < K-i; j++) {
        cnt += dp[l-1-j];
        ans.push_back(l-1-j);
      }

      if (cnt > A && cnt < 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