Submission #1250895

#	Time	Username	Problem	Language	Result	Execution time	Memory
1250895		lukameladze	Triple Peaks (IOI25_triples)	C++20	75.29 / 100	116 ms	16964 KiB

triples

#pragma GCC optimize("Ofast")
#pragma GCC optimize ("O3")
#pragma GCC optimization ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
#include "triples.h"
#include <vector>
#include <algorithm>
#include <cstdio>
#include <cassert>
#include <iostream>
#include <cmath>
#define pb push_back
using namespace std;
int check(int i, int j, int k, vector<int>& h) {
    int x = h[i];
    int y = h[j];
    int z = h[k];
    if (x > y) swap(x, y);
    if (y > z) swap(y, z);
    if (x > z) swap(x, z);
    if (x == j - i && y == k - j && z == k - i) return 1;
    if (x == k - j && y == j - i && z == k - i) return 1;
    return 0;
}
long long count_triples(std::vector<int> H) {
    int n = H.size();
    long long ans = 0;
    vector <int> h(n);
    for (int i = 0; i < n; i++) {
        h[i] = H[i];
        // cout<<h[i]<<" ";
    }
    // cout<<"\n";
    for (int i = 0; i < n; i++) {
        int k = h[i] + i;
        if (k <= i + 1 || k >= n) continue;
        int j = h[k] + i;
        if (j > i && j < k) {
            ans += check(i, j, k, h);
        }
        int j2 = k - h[k];
        if (j2 > i && j2 < k && j2 != j) {
            ans += check(i, j2, k, h);
        }
    }

    
    for (int k = 0; k < n; k++) {
        int i = k - h[k];
        if (i < 0 || i >= k) continue;
        int j = h[i] + i;
        if (j > i && j < k) {
            ans += check(i, j, k, h);
        }
        int j2 = k - h[i];
        if (j2 > i && j2 < k && j2 != j) {
            ans += check(i, j2, k, h);
        }
    }

    
    for (int i = 0; i < n; i++) {
        int j = h[i] + i;
        int k = h[j] + i;

        //  cout << "i: " << i << ", j: " << j << ", k: " << k << " " << check(i, j, k, h) << "\n";
        if (j < i + 1 || j > n) continue;
       
        if (k > j && k < n) {
            
            ans += check(i, j, k, h);
        }
    }

    // for (int i = 0; i < n; i++) {
    //     for (int j = i + 1; j < n; j++) {
    //         for (int k = j + 1; k < n; k++) {
    //             if (check(i, j, k, h) && k - i == h[j] && h[i] == j - i && h[k] == k - j) {
    //                 res++;
    //                 cout << "i: " << i << ", j: " << j << ", k: " << k << "\n";
    //             }
    //         }
    //     }
    // }
    
    // cout << "res: " << res << "\n";
    // cout << "ans: " << ans << "\n";

    vector <vector<int>> vec(2 * n + 1);
    for (int i = 0; i < n; i++) {
        vec[h[i] - i + n].pb(i);
    }
    int b = 400;
    for (int dif = 0; dif <= 2 * n; dif++) {

        if (vec[dif].size() < b) {
            for (int idi = 0; idi < vec[dif].size(); idi++) {
                for (int idj = idi + 1; idj < vec[dif].size(); idj++) {
                    int i = vec[dif][idi];
                    int j = vec[dif][idj];
                    int k = h[j] + i;
                    if (k > j && k < n && h[j] == k - i && h[i] != h[k]) {
                        ans += check(i, j, k, h);
                    }
                }
            }
        } else {
            int act = dif - n;
            for (int k = 2; k < n; k++) {
                int i2 = k - h[k] - act;
                if (i2 < 0 || i2 % 2) continue;
                int i = i2 / 2;
                if (i < 0 || i >= n) continue;
                int j = h[k] + i;
                if (j > i && j < k && h[j] == k - i && h[i] != h[k]) {
                    ans += check(i, j, k, h);
                }
            }
        }
    }
    return ans;
}

std::vector<int> construct_range(int M, int K) {
    vector <int> v;
    for (int i = 0; i < M; i++) {
        if (i % 3 == 0) v.pb(2);
        else v.pb(1);
    }
    return v;
}

• 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: 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