Submission #612612

#	Time	Username	Problem	Language	Result	Execution time	Memory
612612		Jomnoi	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	942 ms	222524 KiB

skyscraper

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;

const short MAX_N = 30000;
const int MAX_W = 7350000;

short qb[MAX_W], qp[MAX_W];
short B[MAX_N], P[MAX_N];
gp_hash_table <short, int> dist[MAX_N];
vector <short> graph[MAX_N];

int main() {
    short N, M;
    cin >> N >> M;
    for(short i = 0; i < M; i++) {
        cin >> B[i] >> P[i];

        graph[B[i]].push_back(P[i]);
    }

    for(short i = 0; i < N; i++) {
        sort(graph[i].begin(), graph[i].end());
        graph[i].resize(unique(graph[i].begin(), graph[i].end()) - graph[i].begin());
    }

    int l = 0, r = 0;
    qb[r] = B[0];
    qp[r++] = P[0];
    dist[B[0]][P[0]] = 0;
    while(l < r) {
        short b = qb[l], p = qp[l++];

        if(b == B[1]) {
            cout << dist[b][p];
            return 0;
        }
        if(b - p >= 0 and dist[b - p].find(p) == dist[b - p].end()) {
            dist[b - p][p] = dist[b][p] + 1;
            qb[r] = b - p;
            qp[r++] = p;
        }
        if(b + p < N and dist[b + p].find(p) == dist[b + p].end()) {
            dist[b + p][p] = dist[b][p] + 1;
            qb[r] = b + p;
            qp[r++] = p;
        }

        for(short p2 : graph[b]) {
            if(b - p2 >= 0 and dist[b - p2].find(p2) == dist[b - p2].end()) {
                dist[b - p2][p2] = dist[b][p] + 1;
                qb[r] = b - p2;
                qp[r++] = p2;
            }
            if(b + p2 < N and dist[b + p2].find(p2) == dist[b + p2].end()) {
                dist[b + p2][p2] = dist[b][p] + 1;
                qb[r] = b + p2;
                qp[r++] = p2;
            }
        }
    }
    cout << -1;
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43