Submission #1286348

#	Time	Username	Problem	Language	Result	Execution time	Memory
1286348		sampaio_kk	3개의 봉우리 (IOI25_triples)	C++20	0.01 / 100	489 ms	12936 KiB

triples

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

long long count_triples(vector<int> H) {
    int N = H.size();
    long long ans = 0;
    vector<vector<int>> pos(N+1);
    for(int i = 0; i < N; i++) if(H[i] <= N) pos[H[i]].push_back(i);

    for(int i = 0; i < N; i++){
        for(int j = i+1; j < min(N,i+2000); j++){ // limitar distância para √N ≈ 2000
            int a = j-i;
            int x = H[i], y = H[j];
            int sum = x+y;
            if(sum <= N){
                auto &v = pos[sum];
                auto it = upper_bound(v.begin(), v.end(), j);
                ans += v.end() - it;
            }
        }
    }
    return ans;
}

vector<int> construct_range(int M, int K){
    int N = min(M, (int)sqrt(K)+10);
    vector<int> H(N);
    for(int i = 0; i < N; i++) H[i] = (i%100)+1;
    return H;
}

• 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: 0.0084 / 5
• Subtask 10: 0.0029 / 5
• Subtask 11: 0.0017 / 5
• Subtask 12: 0.0007 / 5