Submission #1251835

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251835		tranvinhhuy2010	Triple Peaks (IOI25_triples)	C++20	70 / 100	204 ms	24692 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, vector <int>> m;

ll count_triples(vector <int> H) {
    n = H.size();
    ll cnt = 0;
    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(H[l + x] == y) cnt++;
                if(y != x && H[l + y] == y) cnt++;
            }
        }
        int r = j + H[j];
        if(r < n)
        {
            int x = H[r];
            int y = H[j] - x;
            if(y > 0)
            {
                if(H[j + x] == y) cnt++;
                if(y != x && H[j + y] == y) cnt++;
            }
        }
    }

    for (int k = 0; k < n; ++k) {
        int hk = H[k];

        for (int i : m[k - hk]) {
            int j1 = i + H[i];
            int j2 = i + hk;

            if (j1 < k && H[j1] == k-i) cnt++;
            if (j2 < k && j2 != j1 && H[j2] == k-i) cnt++;
        }

        m[k + H[k]].push_back(k);
    }

    return cnt;
}

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: 19 / 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