Submission #1251409

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251409		tranvinhhuy2010	Triple Peaks (IOI25_triples)	C++20	0 / 100	100 ms	30648 KiB

triples

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

using namespace std;

typedef long long ll;

const int nmax = 2e5 + 5;
int n;
unordered_map <int, set <int>> mk;

ll count_triples(vector<int> H) {
    n = H.size();
    ll cnt = 0;
    set<tuple<int, int, int>> seen;

    for (int j = 0; j < n; j++) {
        int l = j - H[j];
        if (l >= 0) {
            int x = H[l];
            int y = H[j] - x;
            if (y > 0) {
                if (l + x < n && H[l + x] == y) {
                    int i = l, k = l + x + y;
                    if (k < n && i < j && j < k) seen.emplace(i, j, k);
                }
                if (y != x && l + y < n && H[l + y] == y) {
                    int i = l, k = l + y + x;
                    if (k < n && i < j && j < k) seen.emplace(i, j, k);
                }
            }
        }

        int r = j + H[j];
        if (r < n) {
            int x = H[r];
            int y = H[j] - x;
            if (y > 0) {
                if (j + x < n && H[j + x] == y) {
                    int i = j - x, k = r;
                    if (i >= 0 && i < j && j < k) seen.emplace(i, j, k);
                }
                if (y != x && j + y < n && H[j + y] == y) {
                    int i = j - y, k = r;
                    if (i >= 0 && i < j && j < k) seen.emplace(i, j, k);
                }
            }
        }

        mk[j - H[j]].insert(j);
    }

    for (int i = 0; i < n; i++) {
        mk[i - H[i]].erase(i);

        for (int k : mk[i + H[i]]) {
            if (k <= i) continue;

            int j1 = i + H[i], j2 = i + H[k];
            if (j1 < k && j1 < n && H[j1] == k - i) seen.emplace(i, j1, k);
            if (j2 < k && j2 < n && H[j2] == k - i) seen.emplace(i, j2, k);
        }
    }

    return seen.size();
}

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

• 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: 0 / 5
• Subtask 8: 0 / 5
• Subtask 9: 0 / 5
• Subtask 10: 0 / 5
• Subtask 11: 0 / 5
• Subtask 12: 0 / 5