Package g2601_2700.s2642_design_graph_with_shortest_path_calculator

Class Graph

java.lang.Object
g2601_2700.s2642_design_graph_with_shortest_path_calculator.Graph
public class Graph extends Object
2642 - Design Graph With Shortest Path Calculator.

Hard

There is a directed weighted graph that consists of n nodes numbered from 0 to n - 1. The edges of the graph are initially represented by the given array edges where edges[i] = [fromi, toi, edgeCosti] meaning that there is an edge from fromi to toi with the cost edgeCosti.

Implement the Graph class:

  • Graph(int n, int[][] edges) initializes the object with n nodes and the given edges.
  • addEdge(int[] edge) adds an edge to the list of edges where edge = [from, to, edgeCost]. It is guaranteed that there is no edge between the two nodes before adding this one.
  • int shortestPath(int node1, int node2) returns the minimum cost of a path from node1 to node2. If no path exists, return -1. The cost of a path is the sum of the costs of the edges in the path.

Example 1:

Input [“Graph”, “shortestPath”, “shortestPath”, “addEdge”, “shortestPath”] [[4, [[0, 2, 5], [0, 1, 2], [1, 2, 1], [3, 0, 3]]], [3, 2], [0, 3], 1, 3, 4, [0, 3]]

Output: [null, 6, -1, null, 6]

Explanation:

Graph g = new Graph(4, [[0, 2, 5], [0, 1, 2], [1, 2, 1], [3, 0, 3]]);

g.shortestPath(3, 2); // return 6. The shortest path from 3 to 2 in the first diagram above is 3 -> 0 -> 1 -> 2 with a total cost of 3 + 2 + 1 = 6.

g.shortestPath(0, 3); // return -1. There is no path from 0 to 3.

g.addEdge([1, 3, 4]); // We add an edge from node 1 to node 3, and we get the second diagram above.

g.shortestPath(0, 3); // return 6. The shortest path from 0 to 3 now is 0 -> 1 -> 3 with a total cost of 2 + 4 = 6.

Constraints:

  • 1 <= n <= 100
  • 0 <= edges.length <= n * (n - 1)
  • edges[i].length == edge.length == 3
  • 0 <= fromi, toi, from, to, node1, node2 <= n - 1
  • 1 <= edgeCosti, edgeCost <= 106
  • There are no repeated edges and no self-loops in the graph at any point.
  • At most 100 calls will be made for addEdge.
  • At most 100 calls will be made for shortestPath.

  • Constructor Details

    • Graph

      public Graph(int n, int[][] edges)

  • Method Details

    • addEdge

      public void addEdge(int[] edge)

    • shortestPath

      public int shortestPath(int node1, int node2)