Submission #1251375

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251375		flashmt	3개의 봉우리 (IOI25_triples)	C++20	34 / 100	2096 ms	4272 KiB

triples

#include "triples.h"
#include <bits/stdc++.h>
#ifdef LOCAL
#include "Debug.h"
#else
#define debug(...) 42
#endif
using namespace std;

long long calc(vector<int> h)
{
  int n = size(h);
  vector<int> l(n, -1), r(n, -1);
  for (int i = 0; i < n; i++)
  {
    if (h[i] <= i)
      l[i] = i - h[i];
    if (i + h[i] < n)
      r[i] = i + h[i];
  }

  long long res = 0;
  for (int i = 0; i < n; i++)
  {
    int j = r[i];
    if (j < 0)
      continue;

    // 2.3..5
    if (r[j] >= 0 && h[r[j]] == h[i] + h[j])
      res++;

    // 2.5..3
    if (h[j] > h[i])
    {
      int k = j + h[j] - h[i];
      if (k < n && l[k] == j)
        res++;
    }

    // 2..5.3
    for (int k = i + 1; k < n; k++)
      if (l[k] == j && h[k] != h[i] && h[i + h[k]] == h[i] + h[k])
        res++;

    // 5.3..2
    if (h[j] < h[i])
    {
      int k = i + h[j];
      if (r[k] == j && h[k] != h[j])
        res++;
    }
  }

  for (int i = 0; i < n; i++)
  {
    int j = l[i];
    if (j < 0)
      continue;

    // 5.2..3
    if (l[j] >= 0 && h[l[j]] == h[i] + h[j])
      res++;

    // 3.2..5
    int k = i + h[j];
    if (r[j] != i && k < n && h[k] == h[i] + h[j])
      res++;
  }

  return res;
}

long long count_triples(vector<int> h) {
  return calc(h);
}

vector<int> construct_range(int M, int K) {
  return {1, 1, 1};
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 0 / 6
• Subtask 3: 10 / 10
• Subtask 4: 0 / 11
• Subtask 5: 16 / 16
• Subtask 6: 0 / 19
• Subtask 7: 0 / 5
• Subtask 8: 0 / 5
• Subtask 9: 0 / 5
• Subtask 10: 0 / 5
• Subtask 11: 0 / 5
• Subtask 12: 0 / 5