Submission #1253405

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253405		fve5	Triple Peaks (IOI25_triples)	C++20	5.29 / 100	16 ms	2376 KiB

triples

#include <bits/stdc++.h>
#include "triples.h"
using namespace std;

typedef long long i64;
constexpr int MAXN = 50000;

i64 count_triples(vector<int> H) {
    auto check = [&](int i, int j, int k) {
        array<int, 3> h = {H[i], H[j], H[k]};
        array<int, 3> d = {abs(i - j), abs(i - k), abs(j - k)};
        sort(h.begin(), h.end());
        sort(d.begin(), d.end());
        return h == d;
    };

    int N = H.size();
    i64 ans = 0;
    for (int i = 0; i < N; i++) {
        int j = i + H[i];
        if (j >= N) continue;
        
        int k1 = j - H[j];
        if (k1 >= 0) {
            ans += check(i, j, k1);
        }

        int k2 = i + H[j];
        if (k2 < N) {
            ans += check(i, j, k2);
        }
    } 

    return ans;
}

vector<int> construct_range(int M, int K) {
    vector<int> A(M);
    iota(A.begin(), A.end(), 0);
    A[0] = 1;
    return A;
}

• 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: 3 / 5
• Subtask 8: 1.245 / 5
• Subtask 9: 0.4998 / 5
• Subtask 10: 0.2143 / 5
• Subtask 11: 0.25 / 5
• Subtask 12: 0.0833 / 5