Package g0601_0700.s0685_redundant_connection_ii

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    685 - Redundant Connection II.

    Hard

    In this problem, a rooted tree is a directed graph such that, there is exactly one node (the root) for which all other nodes are descendants of this node, plus every node has exactly one parent, except for the root node which has no parents.

    The given input is a directed graph that started as a rooted tree with n nodes (with distinct values from 1 to n), with one additional directed edge added. The added edge has two different vertices chosen from 1 to n, and was not an edge that already existed.

    The resulting graph is given as a 2D-array of edges. Each element of edges is a pair <code>u<sub>i</sub>, v<sub>i</sub></code> that represents a directed edge connecting nodes <code>u<sub>i</sub></code> and <code>v<sub>i</sub></code>, where <code>u<sub>i</sub></code> is a parent of child <code>v<sub>i</sub></code>.

    Return an edge that can be removed so that the resulting graph is a rooted tree of n nodes. If there are multiple answers, return the answer that occurs last in the given 2D-array.

    Example 1:

    Input: edges = [1,2,1,3,2,3]

    Output: 2,3

    Example 2:

    Input: edges = [1,2,2,3,3,4,4,1,1,5]

    Output: 4,1

    Constraints:

    • n == edges.length

    • 3 &lt;= n &lt;= 1000

    • edges[i].length == 2

    • <code>1 <= u<sub>i</sub>, v<sub>i</sub><= n</code>

    • <code>u<sub>i</sub> != v<sub>i</sub></code>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final IntArray findRedundantDirectedConnection(Array<IntArray> edges)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait