Submission #786108

#	Time	Username	Problem	Language	Result	Execution time	Memory
786108		devariaota	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	26 ms	34636 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define fi first
#define se second

queue<pair<int, int>> q;
vector<int> adj[30005];
int dist[2005][2005];
bool vis[2005];

int main() { 
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    int n, m;
    cin >> n >> m;
    int s, f;
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        if (i == 0) s = u;
        if (i == 1) f = u;
    }
    for (int i = 0; i <= 2000; i++) {
        for (int j = 0; j <= 2000; j++) dist[i][j] = -1;
    }
    for (auto x : adj[s]) {
        q.push({s, x});
        dist[s][x] = 0;
    }
    vis[s] = 1;
    while (!q.empty()) {
        int x = q.front().fi, d = q.front().se;
        q.pop();
        if (x == f) {
            cout << dist[x][d] << "\n";
            return 0;
        }
        if (x - d >= 0 and !vis[x - d]) {
            vis[x - d] = 1;
            for (auto u : adj[x - d]) {
                q.push({x - d, u});
                dist[x - d][u] = dist[x][d] + 1;
            }
        }
        if (x - d >= 0 and dist[x - d][d] == -1) {
            q.push({x - d, d});
            dist[x - d][d] = dist[x][d] + 1;
        }
        if (x + d < n and !vis[x + d]) {
            vis[x + d] = 1;
            for (auto u : adj[x + d]) {
                q.push({x + d, u});
                dist[x + d][u] = dist[x][d] + 1;
            }
        }
        if (x + d < n and dist[x + d][d] == -1) {
            q.push({x + d, d});
            dist[x + d][d] = dist[x][d] + 1;
        }
    }
    cout << -1 << "\n";
}  

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:18:9: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
   18 |     int s, f;
      |         ^
skyscraper.cpp:37:9: warning: 'f' may be used uninitialized in this function [-Wmaybe-uninitialized]
   37 |         if (x == f) {
      |         ^~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43