86 lines
2.2 KiB
Java
86 lines
2.2 KiB
Java
/*
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Refer https://www.geeksforgeeks.org/dijkstras-shortest-path-algorithm-greedy-algo-7/
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for better understanding
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*/
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package DataStructures.Graphs;
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class dijkstras{
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int k=9;
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int minDist(int dist[], Boolean Set[])
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{
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int min = Integer.MAX_VALUE, min_index = -1;
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for (int r = 0; r < k; r++)
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if (Set[r] == false && dist[r] <= min) {
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min = dist[r];
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min_index = r;
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}
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return min_index;
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}
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void print(int dist[])
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{
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System.out.println("Vertex \t\t Distance");
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for (int i = 0; i < k; i++)
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System.out.println(i + " \t " + dist[i]);
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}
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void dijkstra(int graph[][], int src)
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{
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int dist[] = new int[k];
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Boolean Set[] = new Boolean[k];
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for (int i = 0; i < k; i++) {
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dist[i] = Integer.MAX_VALUE;
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Set[i] = false;
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}
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dist[src] = 0;
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for (int c = 0; c < k - 1; c++) {
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int u = minDist(dist, Set);
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Set[u] = true;
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for (int v = 0; v < k; v++)
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if (!Set[v] && graph[u][v] != 0 && dist[u] != Integer.MAX_VALUE && dist[u] + graph[u][v] < dist[v])
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dist[v] = dist[u] + graph[u][v];
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}
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print(dist);
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}
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public static void main(String[] args)
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{
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int graph[][] = new int[][] { { 0, 4, 0, 0, 0, 0, 0, 8, 0 },
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{ 4, 0, 8, 0, 0, 0, 0, 11, 0 },
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{ 0, 8, 0, 7, 0, 4, 0, 0, 2 },
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{ 0, 0, 7, 0, 9, 14, 0, 0, 0 },
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{ 0, 0, 0, 9, 0, 10, 0, 0, 0 },
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{ 0, 0, 4, 14, 10, 0, 2, 0, 0 },
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{ 0, 0, 0, 0, 0, 2, 0, 1, 6 },
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{ 8, 11, 0, 0, 0, 0, 1, 0, 7 },
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{ 0, 0, 2, 0, 0, 0, 6, 7, 0 } };
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dijkstras t = new dijkstras();
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t.dijkstra(graph, 0);
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}//main
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}//djikstras
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/*
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OUTPUT :
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Vertex Distance
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0 0
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1 4
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2 12
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3 19
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4 21
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5 11
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6 9
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7 8
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8 14
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*/
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