Submission #495665

#	Time	Username	Problem	Language	Result	Execution time	Memory
495665		vishesh312	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	193 ms	67724 KiB

skyscraper

#include "bits/stdc++.h"
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using ordered_set = tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>;
*/

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x) (int)(x).size()

using ll = long long;
const int mod = 1e9+7;

void solve(int tc) {
    int n, m, s, t;
    cin >> n >> m;
    vector<set<int>> ju(n);
    set<int> p;
    vector<vector<pair<int, int>>> adj(n);
    for (int i = 0; i < m; ++i) {
        int a, b;
        cin >> a >> b;
        ju[a].insert(b);
        p.insert(b);
        if (i==0) s = a;
        if (i==1) t = a;
    }
    for (int i = 0; i < n; ++i) {
        for (int x : ju[i]) {
            int cur = i;
            while (cur+x < n) {
                cur += x;
                adj[i].push_back({cur, (cur-i)/x});
                if (ju[cur].count(x))
                    break;
            }
            cur = i;
            while (cur-x >= 0) {
                cur -= x;
                adj[i].push_back({cur, (i-cur)/x});
                if (ju[cur].count(x))
                    break;
            }
        }
    }
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
    pq.push({0, s});
    vector<int> dist(n, (1<<30));
    dist[s] = 0;
    while (!pq.empty()) {
        auto [d, u] = pq.top();
        pq.pop();
        if (dist[u] < d)
            continue;
        for (auto [v, dd] : adj[u]) {
            if (dist[v] <= dist[u]+dd)
                continue;
            dist[v] = dist[u] + dd;
            pq.push({dist[v], v});
        }
    }
    cout << (dist[t]==(1<<30)?-1:dist[t]) << '\n';
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    int tc = 1;
    //cin >> tc;
    for (int i = 1; i <= tc; ++i) solve(i);
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void solve(int)':
skyscraper.cpp:51:11: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
   51 |     dist[s] = 0;
      |           ^
skyscraper.cpp:64:20: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
   64 |     cout << (dist[t]==(1<<30)?-1:dist[t]) << '\n';
      |                    ^

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