Submission #303380

#	Time	Username	Problem	Language	Result	Execution time	Memory
303380		rama_pang	Packing Biscuits (IOI20_biscuits)	C++14	100 / 100	17 ms	896 KiB

biscuits

#include "biscuits.h"
#include <bits/stdc++.h>
using namespace std;

long long count_tastiness(long long x, vector<long long> a) {
  int k = (int) a.size();
  auto b = a;
  for (int i = 1; i < k; i++) {
    b[i] += b[i - 1] / 2;
  }
  
  while (b.back() > 0) {
    k += 1;
    a.emplace_back(0);
    b.emplace_back(b.back() / 2);
  }

  vector<long long> dp_on(k); // dp_on[i] = first i bits, i-th bit is on
  vector<long long> dp_off(k); // dp_off[i] = first i bits, i-th bit is off
  for (int i = 0; i < k; i++) {
    dp_off[i] = (i > 0 ? (dp_on[i - 1] + dp_off[i - 1]) : 1);
    if (b[i] < x) {
      dp_on[i] = 0;
    } else {
      dp_on[i] = 1;
      long long need = max(0ll, x - a[i]);
      for (int j = i - 1; j >= 0; j--) {
        need = need * 2;
        if (b[j] >= need + x) {
          dp_on[i] += dp_off[j]; // turn the j-th bit off
          need = max(0ll, need + x - a[j]); // turn the j-th bit on
        } else {
          need = max(0ll, need - a[j]); // the j-th bit can only be off
        }
      }
    }
  }
  return dp_on[k - 1] + dp_off[k - 1];
}

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 21 / 21
• Subtask 4: 35 / 35
• Subtask 5: 23 / 23