Cod sursa(job #2851574)

Utilizator SlavicGGuzun Veaceslav SlavicG Data 18 februarie 2022 20:25:32
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.73 kb
#include "bits/stdc++.h"
using namespace std;
 
#define ll long long
 
#define       forn(i,n)              for(int i=0;i<n;i++)
#define          all(v)              v.begin(), v.end()
#define         rall(v)              v.rbegin(),v.rend()
 
#define            pb                push_back
#define          sz(a)               (int)a.size()

template<typename T>
pair<vector<T>, vector<int>> Dijkstra(int start, vector<vector<pair<int,T>>> adj, T mx) {
    int n = adj.size();
    priority_queue<pair<T, int>> q;

    vector<T> dist(n, mx);
    vector<int> parent(n, -1); 
    dist[start] = 0;

    q.push({0, start});

    while(!q.empty()) {
        int u = q.top().second;
        T dist_u = -q.top().first;
        q.pop();
        if(dist_u != dist[u]) continue;

        for(auto x: adj[u]) {
            int v = x.first;
            T w = x.second;

            if(dist[v] > dist[u] + w) {
                dist[v] = dist[u] + w;
                parent[v] = u;
                q.push({-dist[v], v});
            }
        }
    }

    return {dist, parent};
    //start, adjlist, fill_max
}

void solve() {
    int n, m;
    cin >> n >> m;
    vector<vector<pair<int, int>>> adj(n);
    for(int i = 0;i < m; ++i) {
        int u, v, w;
        cin >> u >> v >> w; --u, --v;
        adj[u].pb({v, w});
    }

    vector<int> dist = Dijkstra(0, adj, (int)1e9).first;
    for(int i = 1;i < n; ++i) {
        cout << (dist[i] == (ll)1e16 ? 0 : dist[i]) << " ";
    }
} 
 
int32_t main() {
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int t = 1;
    //cin >> t;
    while(t--) {
        solve();
    }
}