Submission #634651

#	Time	Username	Problem	Language	Result	Execution time	Memory
634651		rockoana	Rice Hub (IOI11_ricehub)	C++17	100 / 100	13 ms	2516 KiB

ricehub

#include <vector>

#include "ricehub.h"

using namespace std;

vector<long long> s;
long long cost(int st, int dr, int X[]) {
  int mid = (st + dr) / 2;
  // X[mid + 1] - X[mid] + X[mid + 2] - X[mid]...X[dr] - X[mid];
  // X[mid] - X[mid] + X[mid] - X[mid - 1] + ... + X[mid] - X[st]

  long long res = s[dr] - s[mid] - s[mid];
  if (st != 0) {
    res += s[st - 1];
  }

  if ((dr - st + 1) % 2 == 1) {
    res += X[mid];
  }

  return res;
}

int besthub(int R, int L, int X[], long long B) {
  s.assign(R, 0);
  for (int i = 0; i < R; i++) {
    s[i] += X[i];
    if (i != 0) {
      s[i] += s[i - 1];
    }
  }

  int st = 0;
  int res = 0;
  for (int i = 0; i < R; i++) {
    while (cost(st, i, X) > B) {
      st++;
    }

    res = max(res, i - st + 1);
  }

  return res;
}

• Subtask 1: 17 / 17
• Subtask 2: 25 / 25
• Subtask 3: 26 / 26
• Subtask 4: 32 / 32