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I used standart Topological sort algorithm, but if node==5000 it says stack overflow, any one know how to do it without recursion.
Thanks

ya, it can be done using indegree. indegree indicates number of edges coming into u from any other vertices.

1. output and remove any node u, elements of V, such that indegree = 0.
2. decrease all indegree[v] by one, if (u,v) is an edge.
3. jump to 1 untill all node has been removed.

Note that, you will always find at least one node of indegree 0 if there exists no cycle in the graph.