What are some common graph algorithms implemented in C++?

What are some common graph algorithms implemented in C++?

Some common graph algorithms in C++ include Dijkstra's algorithm, Depth-First Search (DFS), and Breadth-First Search (BFS). Would you like to know more about any specific algorithm?

Can you explain Dijkstra's algorithm?

Dijkstra's algorithm finds the shortest path from a source node to all other nodes in a weighted graph. It uses a priority queue to explore the nearest unvisited node and updates the shortest path to its neighbors.

How do I implement Dijkstra's algorithm in C++?

To implement Dijkstra's algorithm in C++, you can use a priority queue from the STL. Start by initializing distances, then repeatedly extract the minimum distance node and update its neighbors.

Can you provide a sample code for that?

Sure! Here's a simple implementation:

#include <iostream>
#include <vector>
#include <queue>
#include <climits>
using namespace std;

void dijkstra(int src, vector<vector<pair<int, int>>>& graph) {
    vector<int> dist(graph.size(), INT_MAX);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    dist[src] = 0;
    pq.push({0, src});

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

        for (auto& neighbor : graph[u]) {
            int v = neighbor.first;
            int weight = neighbor.second;
            if (dist[u] + weight < dist[v]) {
                dist[v] = dist[u] + weight;
                pq.push({dist[v], v});
            }
        }
    }
    // Output distances
}

This code initializes distances and uses a priority queue to find the shortest paths.