Submission #839351

#	Time	Username	Problem	Language	Result	Execution time	Memory
839351		popovicirobert	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	285 ms	112532 KiB

skyscraper

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

constexpr int MAXN = 30'000;
constexpr int MAXP = 30'000;

bitset<MAXP + 1> visited[MAXN];

struct Node {
    unsigned short b, p;
    int dist;
};
 
int main() {
#ifdef HOME
    ifstream cin("input.in");
    ofstream cout("output.out");
#endif
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
 
    int n, m;
    cin >> n >> m;

    vector<unsigned short> b(m), p(m);
    vector<vector<unsigned short>> P(n);
    for (int i = 0; i < m; i++) {
        cin >> b[i] >> p[i];
        P[b[i]].push_back(p[i]);
    }

    deque<Node> Q;
    Q.push_front({b[0], p[0], 0});
    visited[b[0]][p[0]] = true;

    while (Q.size()) {
        auto curr = Q.front();
        Q.pop_front();

        auto Go = [&Q](int b, int p, int dist, bool front) {
            if (!visited[b][p]) {
                if (front) {
                    Q.push_front({b, p, dist});
                } else {
                    Q.push_back({b, p, dist});
                }
                visited[b][p] = true;
            }
        };

        if (curr.b == b[1]) {
            cout << curr.dist << "\n";
            return 0;
        }

        for (auto p : P[curr.b]) {
            Go(curr.b, p, curr.dist, true);
        }
        if (curr.b >= curr.p) {
            Go(curr.b - curr.p, curr.p, curr.dist + 1, false);
        }
        if (curr.b + curr.p < n) {
            Go(curr.b + curr.p, curr.p, curr.dist + 1, false);
        }
    }

    cout << -1 << "\n";
 
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In lambda function:
skyscraper.cpp:44:35: warning: narrowing conversion of 'b' from 'int' to 'short unsigned int' [-Wnarrowing]
   44 |                     Q.push_front({b, p, dist});
      |                                   ^
skyscraper.cpp:44:38: warning: narrowing conversion of 'p' from 'int' to 'short unsigned int' [-Wnarrowing]
   44 |                     Q.push_front({b, p, dist});
      |                                      ^
skyscraper.cpp:46:34: warning: narrowing conversion of 'b' from 'int' to 'short unsigned int' [-Wnarrowing]
   46 |                     Q.push_back({b, p, dist});
      |                                  ^
skyscraper.cpp:46:37: warning: narrowing conversion of 'p' from 'int' to 'short unsigned int' [-Wnarrowing]
   46 |                     Q.push_back({b, p, dist});
      |                                     ^

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