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Copy pathprim.java
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76 lines (68 loc) · 2 KB
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import java.util.*;
public class prim {
static class Edge{
int src;
int dest;
int wt;
public Edge(int s, int d, int w){
this.src =s;
this.dest =d;
this.wt =w;
}
}
public static void createGraph(ArrayList<Edge> graph[]){
for(int i=0; i<graph.length; i++){
graph[i] = new ArrayList<>();
}
//vertex 0
graph[0].add(new Edge(0, 1, 10));
graph[0].add(new Edge(0, 2, 15));
graph[0].add(new Edge(0, 3, 30));
//vertex 1
graph[1].add(new Edge(1, 3, 40));
graph[1].add(new Edge(1, 0, 10));
//vertex 2
graph[2].add(new Edge(2, 3, 50));
graph[2].add(new Edge(2, 0, 15));
//vertex 3
graph[3].add(new Edge(3, 0, 30));
graph[3].add(new Edge(3, 1, 40));
graph[3].add(new Edge(3, 2, 50));
}
static class Pair implements Comparable<Pair>{
int v;
int cost;
public Pair(int v, int cost){
this.v = v;
this.cost = cost;
}
@Override
public int compareTo(Pair p2){
return this.cost - p2.cost;
}
}
public static void prims(ArrayList<Edge> graph[]){
boolean vis[] = new boolean[graph.length];
PriorityQueue<Pair> pq = new PriorityQueue<>();
pq.add(new Pair(0, 0));
int finalCost = 0;
while(!pq.isEmpty()){
Pair curr = pq.remove();
if(!vis[curr.v]){
vis[curr.v] = true;
finalCost += curr.cost;
for(int i=0; i<graph[curr.v].size(); i++){
Edge e = graph[curr.v].get(i);
pq.add(new Pair(e.dest, e.wt));
}
}
}
System.out.print("Mst final cost " +finalCost);
}
public static void main(String[] args) {
int V = 4;
ArrayList<Edge> graph[] = new ArrayList[V];
createGraph(graph);
prims(graph);
}
}