Submission #1251089

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251089		fadyscube	Triple Peaks (IOI25_triples)	C++20	1.35 / 100	61 ms	1956 KiB

triples

#include "triples.h"
#include <set>

using namespace std;

int checkTriple (vector<int> &H, int a, int b, int c) {
  if (a == b || b == c || a == c) return 0;
  int n = H.size();
  if (a < 0 || a >= n) return 0;
  multiset<int> ds = {abs(b-a), abs(c-a), abs(c-b)};
  multiset<int> hs = {H[a], H[b], H[c]};
  return (ds == hs ? 1 : 0);
}

long long count_triples(std::vector<int> H) {
  long long ans = 0;
  int n = H.size();
  
  for (int i = n-1; i >= 2; i--) {
    int a = i - H[i];
    if (a + H[a] < i) {
      ans += checkTriple(H, a, a+H[a], i);
    }
    if (a < i - H[a] && i - H[a] != a + H[a]) {
      ans += checkTriple(H, a, i-H[a], i);
    }
  }

  return ans;
}

std::vector<int> construct_range(int M, int K) {
  vector<int> v = {8, 9, 16, 17, 7, 2, 16, 3, 1, 1, 6, 4, 18, 9, 8, 5, 9, 18, 17, 12};
  return v;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 8
• Subtask 2: 0 / 6
• Subtask 3: 0 / 10
• Subtask 4: 0 / 11
• Subtask 5: 0 / 16
• Subtask 6: 0 / 19
• Subtask 7: 1.3333 / 5
• Subtask 8: 0.02 / 5
• Subtask 9: 0.0008 / 5
• Subtask 10: 0.0001 / 5
• Subtask 11: 0 / 5
• Subtask 12: 0 / 5