Package g2301_2400.s2316_count_unreachable_pairs_of_nodes_in_an_undirected_graph

Class Solution

java.lang.Object
g2301_2400.s2316_count_unreachable_pairs_of_nodes_in_an_undirected_graph.Solution
public class Solution extends java.lang.Object
2316 - Count Unreachable Pairs of Nodes in an Undirected Graph.

Medium

You are given an integer n. There is an undirected graph with n nodes, numbered from 0 to n - 1. You are given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi.

Return the number of pairs of different nodes that are unreachable from each other.

Example 1:

Input: n = 3, edges = [[0,1],[0,2],[1,2]]

Output: 0

Explanation: There are no pairs of nodes that are unreachable from each other.

Therefore, we return 0.

Example 2:

Input: n = 7, edges = [[0,2],[0,5],[2,4],[1,6],[5,4]]

Output: 14

Explanation: There are 14 pairs of nodes that are unreachable from each other: [[0,1],[0,3],[0,6],[1,2],[1,3],[1,4],[1,5],[2,3],[2,6],[3,4],[3,5],[3,6],[4,6],[5,6]].

Therefore, we return 14.

Constraints:

  • 1 <= n <= 105
  • 0 <= edges.length <= 2 * 105
  • edges[i].length == 2
  • 0 <= ai, bi < n
  • ai != bi
  • There are no repeated edges.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    countPairs(int n, int[][] edges)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • countPairs

      public long countPairs(int n, int[][] edges)