73 lines
2.3 KiB
C#
73 lines
2.3 KiB
C#
using System;
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using System.Collections.Generic;
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namespace Algorithms.Graph
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{
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public class FloydWarshallAlgorithm
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{
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const int INFINITY = (int)1e9;
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public static int[,] AllPairShortestPath(int totalNode, bool isDirected, List<Tuple<int, int, int>> edges)
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{
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int[,] distance = new int[totalNode + 1, totalNode + 1];
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for (int i = 1; i <= totalNode; i++)
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{
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for (int j = 1; j <= totalNode; j++)
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{
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distance[i, j] = i == j ? 0 : INFINITY;
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distance[j, i] = i == j ? 0 : INFINITY;
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}
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}
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foreach (var edge in edges)
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{
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distance[edge.Item1, edge.Item2] = Math.Min(edge.Item3, distance[edge.Item1, edge.Item2]);
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distance[edge.Item2, edge.Item1] = isDirected ? distance[edge.Item2, edge.Item1] : Math.Min(edge.Item3, distance[edge.Item2, edge.Item1]);
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}
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for (int k = 1; k <= totalNode; k++)
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{
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for (int i = 1; i <= totalNode; i++)
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{
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for (int j = 1; j <= totalNode; j++)
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{
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distance[i, j] = Math.Min(distance[i, j], distance[i, k] + distance[k, j]);
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}
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}
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}
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return distance;
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}
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public static void Main()
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{
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List<Tuple<int, int, int>> edges = new List<Tuple<int, int, int>>()
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{
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new Tuple<int, int, int>(1, 4, 10),
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new Tuple<int, int, int>(1, 2, 5),
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new Tuple<int, int, int>(2, 3, 3),
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new Tuple<int, int, int>(3, 4, 1)
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};
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var results = AllPairShortestPath(4, true, edges);
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for (int i = 1; i <= 4; i++)
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{
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for (int j = 1; j <= 4; j++)
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{
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if (results[i, j] >= INFINITY)
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{
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Console.Write("inf ");
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}
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else
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{
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Console.Write($"{results[i, j]} ");
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}
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}
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Console.WriteLine();
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}
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}
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}
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}
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