Tarjan SCC Iterative Count

Problem

Count the strongly connected components of a directed graph with n nodes using an iterative Tarjan algorithm.

Track discovery indices, low-link values, and an explicit DFS work stack so no recursion is used. When low[v] equals index[v], pop the component off the component stack. edges is a list of [u, v] pairs.

Hint

Emit an SCC whenever low[v] == index[v] and pop the component stack down to v.

Test cases

case 1

in: [5,[[0,1],[1,2],[2,0],[3,4],[4,3]]]

expected: 2

case 2

in: [4,[[0,1],[1,2],[2,3]]]

expected: 4

case 3

in: [1,[]]

expected: 1

case 4

in: [3,[[0,1],[1,2],[2,0],[0,2]]]

expected: 1

case 5

in: [6,[[0,1],[1,2],[2,1],[3,4],[4,5],[5,3],[1,3]]]

expected: 3

Starter codePython

def tarjan_scc_count(n, edges):
    # Your code here
    pass

5 test cases · run your code against them in the editor