LESSON 56 / 75·2 min readIntermediate

Graphs in C#

Should knowConcept lesson

Problems to practice

Number of Islands
Course Schedule
Clone Graph
Topological Sort
BFS and DFS traversal
Shortest path in unweighted graph
Union-Find connectivity

Example: BFS using queue

var queue = new Queue<int>();
var visited = new HashSet<int>();
queue.Enqueue(start);
visited.Add(start);

while (queue.Count > 0) {
    int node = queue.Dequeue();
    foreach (var neighbor in graph[node]) {
        if (!visited.Contains(neighbor)) {
            visited.Add(neighbor);
            queue.Enqueue(neighbor);
        }
    }
}

PAUSE & RECALL