Minimum Edge Reversals So Every Node Is Reachable
There is a simple directed graph with n nodes labeled from 0 to n - 1. The graph would form a tree if its edges were bi-directional.
You are given an integer n and a 2D integer array edges, where edges[i] = [ui, vi] represents a directed edge going from node ui to node vi.
An edge reversal changes the direction of an edge, i.e., a directed edge going from node ui to node vi becomes a directed edge going from node vi to node ui.
For every node i in the range [0, n - 1], your task is to independently calculate the minimum number of edge reversals required so it is possible to reach any other node starting from node i through a sequence of directed edges.
Return an integer array answer, where answer[i] is the minimum number of edge reversals required so it is possible to reach any other node starting from node i through a sequence of directed edges.
n = 4, edges = [[2,0],[2,1],[1,3]][1,1,0,2]n = 3, edges = [[1,2],[2,0]][2,0,1]Constraints
- 2 <= n <= 10^5
- edges.length == n - 1
- edges[i].length == 2
- 0 <= ui == edges[i][0] < n
- 0 <= vi == edges[i][1] < n
- ui != vi
- The input is generated such that if the edges were bi-directional, the graph would be a tree.