Dijkstra Algorithm

#include <iostream>
#include <vector>
#include <queue>
#include <functional>

using namespace std;

const int MAX = 1e4 + 5;
vector<pair<int, int>> adj[MAX];
bool visited[MAX];
int dist[MAX];

void Dijkstra(int start)
{
    for (int i = 0; i < MAX; i++)
        dist[i] = INT_MAX;

    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    pq.push({0, start});
    dist[start] = 0;

    while (!pq.empty())
    {
        int u = pq.top().second;
        pq.pop();

        if (visited[u])
            continue;

        visited[u] = true;

        for (int i = 0; i < adj[u].size(); i++)
        {
            int v = adj[u][i].first;
            int weight = adj[u][i].second;

            if (dist[v] > dist[u] + weight)
            {
                dist[v] = dist[u] + weight;
                pq.push({dist[v], v});
            }
        }
    }
}

int main()
{
    int V, E, u, v, w;
    cin >> V >> E;

    for (int i = 0; i < E; i++)
    {
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }

    int start;
    cin >> start;
    Dijkstra(start);

    for (int i = 0; i < V; i++)
        cout << i << " " << dist[i] << endl;

    return 0;
}