Submission #879075

#	Time	Username	Problem	Language	Result	Execution time	Memory
879075		Pelmeni	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	607 ms	13008 KiB

skyscraper

#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;
// #define int long long
typedef pair<int, int> T;
const int oo = 1e9 + 7, K = 30;
const int mod = 998244353;

void solve() {
    int n, m;
    cin >> n >> m;
    vector<vector<T>> g(n + 2);
    vector<vector<int>> doge(n + 1);
    int start, kon;
    for (int i = 0; i < m; i++) {
        int v, j;
        cin >> v >> j;
        if (i == 0) start = v;
        if (i == 1) kon = v;
        doge[v].emplace_back(j);
    }

    vector<int> dist(n + 2, oo);
    set<T> s;
    s.insert({0, start});
    dist[start] = 0;
    while ((int) s.size()) {
        auto [d, v] = *s.begin();
        s.erase(s.begin());
        if (dist[v] < d) continue;
        auto popraw = [&](int what, int from, int c) {
            if (dist[what] > dist[from] + c) {
                dist[what] = dist[from] + c;
                s.insert({dist[what], what});
            }
        };
        for (auto j : doge[v]) {
            for (int u = v - j, k = 1; u >= 0; u -= j, k++) {
                popraw(u, v, k);
            }
            for (int u = v + j, k = 1; u < n; u += j, k++) {
                popraw(u, v, k);
            }
        }
    }
    int ans = dist[kon];
    if (ans == oo) ans = -1;
    cout << ans << "\n";
}

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    //cin >> t;
    while (t--) solve();

    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void solve()':
skyscraper.cpp:26:15: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
   26 |     dist[start] = 0;
      |               ^
skyscraper.cpp:46:23: warning: 'kon' may be used uninitialized in this function [-Wmaybe-uninitialized]
   46 |     int ans = dist[kon];
      |                       ^

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