Package g2901_3000.s2924_find_champion_ii

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    2924 - Find Champion II\.

    Medium

    There are n teams numbered from 0 to n - 1 in a tournament; each team is also a node in a DAG.

    You are given the integer n and a 0-indexed 2D integer array edges of length m representing the DAG , where <code>edgesi = u<sub>i</sub>, v<sub>i</sub></code> indicates that there is a directed edge from team <code>u<sub>i</sub></code> to team <code>v<sub>i</sub></code> in the graph.

    A directed edge from a to b in the graph means that team a is stronger than team b and team b is weaker than team a.

    Team a will be the champion of the tournament if there is no team b that is stronger than team a.

    Return the team that will be the champion of the tournament if there is a unique champion, otherwise, return -1.

    Notes

    • A cycle is a series of nodes <code>a<sub>1</sub>, a<sub>2</sub>, ..., a<sub>n</sub>, a<sub>n+1</sub></code> such that node <code>a<sub>1</sub></code> is the same node as node <code>a<sub>n+1</sub></code>, the nodes <code>a<sub>1</sub>, a<sub>2</sub>, ..., a<sub>n</sub></code> are distinct, and there is a directed edge from the node <code>a<sub>i</sub></code> to node <code>a<sub>i+1</sub></code> for every i in the range [1, n].

    • A DAG is a directed graph that does not have any cycle.

    Example 1:

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

    Output: 0

    Explanation: Team 1 is weaker than team 0. Team 2 is weaker than team 1. So the champion is team 0.

    Example 2:

    Input: n = 4, edges = \[\[0,2],1,3,1,2]

    Output: -1

    Explanation: Team 2 is weaker than team 0 and team 1. Team 3 is weaker than team 1. But team 1 and team 0 are not weaker than any other teams. So the answer is -1.

    Constraints:

    • 1 &lt;= n &lt;= 100

    • m == edges.length

    • 0 &lt;= m &lt;= n * (n - 1) / 2

    • edges[i].length == 2

    • 0 &lt;= edge[i][j] &lt;= n - 1

    • edges[i][0] != edges[i][1]

    • The input is generated such that if team a is stronger than team b, team b is not stronger than team a.

    • The input is generated such that if team a is stronger than team b and team b is stronger than team c, then team a is stronger than team c.

    • 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 Integer findChampion(Integer n, Array<IntArray> edges)

      • Methods inherited from class java.lang.Object

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