// Algorithm: Topological Sort
// Type: Graph, Directed Acyclic Graph (DAG), DFS-based
// Time Complexity: O(V + E)
// Space Complexity: O(V)

function topoSort(graph):
    visited = set()
    stack = []

    for each node in graph:
        if node not in visited:
            dfs(node, visited, stack)

    return reverse(stack)

function dfs(node, visited, stack):
    mark node as visited
    for neighbor in node's adjacency list:
        if neighbor not visited:
            dfs(neighbor, visited, stack)
    stack.push(node)