Submission #1281574

#	Time	Username	Problem	Language	Result	Execution time	Memory
1281574		M_W_13	Triple Peaks (IOI25_triples)	C++20	51 / 100	2118 ms	715172 KiB

triples

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

using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
typedef long long ll;
#define pb push_back
#define st first
#define nd second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(a) a.begin(), a.end()

set<pair<pii, int>> S;

pair<pii, int> sor(int a, int b, int c) {
  int x = min({a, b, c});
  int z = max({a, b, c});
  int y = a + b + c - x - z;
  return {{x, y}, z};
}

long long count_triples(std::vector<int> T) {
  int n = T.size();
  ll ans = 0;
  rep(i, n) {
    int j = i + T[i];
    int k[4];
    if (j < n) {
      k[0] = i + T[j];
      k[1] = i - T[j];
      k[2] = j + T[j];
      k[3] = j - T[j];
      rep(c, 4) {
        if (i == j || i == k[c] || j == k[c]) continue;
        if (k[c] < 0 || k[c] >= n) continue;
        int x = T[i];
        int y = T[j];
        int z = T[k[c]];
        int a = abs(i - j);
        int b = abs(i - k[c]);
        int d = abs(j - k[c]);
        if ((x + y + z) != (2 * max({x, y, z}))) continue;
        if (sor(a, b, d) != sor(x, y, z)) continue;
        S.insert(sor(i, j, k[c]));
      }
    }
    j = i - T[i];
    if (j >= 0) {
      k[0] = i + T[j];
      k[1] = i - T[j];
      k[2] = j + T[j];
      k[3] = j - T[j];
      rep(c, 4) {
        if (i == j || i == k[c] || j == k[c]) continue;
        if (k[c] < 0 || k[c] >= n) continue;
        int x = T[i];
        int y = T[j];
        int z = T[k[c]];
        int a = abs(i - j);
        int b = abs(i - k[c]);
        int d = abs(j - k[c]);
        if ((x + y + z) != (2 * max({x, y, z}))) continue;
        if (sor(a, b, d) != sor(x, y, z)) continue;
        S.insert(sor(i, j, k[c]));
      }
    }
  }
  ans = (long long) S.size();
  // for (auto p: S) {
  //   cout << p.st.st << " " << p.st.nd << " " << p.nd << '\n';
  // }
  vector<int> jakie[2 * n + 1];
  vector<int> jakie2[2 * n + 1];
  int iter[n];
  int iter2[n];
  rep(i, n) {
    int x = T[i] - i + n;
    iter[i] = jakie[x].size();
    jakie[x].pb(i);
  }
  for (int i = n - 1; i >= 0; i--) {
    int x = T[i] + i;
    iter2[i] = jakie2[x].size();
    jakie2[x].pb(i);
  }
  rep(i, n) {
    int x = T[i] - i + n;
    int y = T[i] + i;
    int sz = jakie[x].size();
    int sz1 = jakie[y].size();
    if (sz <= sz1) {
      for (int it = iter[i] - 1; it >= 0; it--) {
        int j = jakie[x][it];
        int k = i + T[j];
        if (k < n && ((T[k] + T[j]) == T[i])) {
          S.insert(sor(i, j, k));
          ans++;
        }
      }
    }
    else {
      for (int it = iter2[i] - 1; it >= 0; it--) {
        int k = jakie2[y][it];
        int j = i - T[k];
        if (j >= 0 && ((T[k] + T[j]) == T[i])) {
          S.insert(sor(i, j, k));
          ans++;
        }
      }
    }
  }
  ans = S.size();
  return ans;
}

std::vector<int> construct_range(int M, int K) {

  return {1, 1, 1};
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 6 / 6
• Subtask 3: 10 / 10
• Subtask 4: 11 / 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