59 lines
1.3 KiB
C++
59 lines
1.3 KiB
C++
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#include <bits/stdc++.h>
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using namespace std;
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void prims(vector<pair<int,int>> adj[], vector<int> &key, vector<int> &parent, vector<bool> &mst, int V, int E, int &ans)
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{
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key[0] = 0;
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for(int count=0; count<V; count++)
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{
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int min = INT_MAX, u;
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//to find the minimum weight of edge from the key array
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for(int i=0;i<V;i++){
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if(!mst[i] && key[i] < min){
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min = key[i];
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u = i;
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}
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}
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mst[u] = true;
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ans += key[u];
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for(auto it: adj[u]){
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int v = it.first;
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int w = it.second;
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if(!mst[v] && w < key[v]){
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key[v] = w;
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parent[v] = u;
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}
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}
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}
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}
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int main(){
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int V,E;
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cout<<"no of vertex:"; cin>>V;
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cout<<"no of edges:"; cin>>E;
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vector<pair<int,int>> adj[V];
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int u,v,wt;
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for(int i=0; i<E; i++){
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cin>> u >> v >> wt;
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adj[u].push_back({v,wt});
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adj[v].push_back({u,wt});
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}
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vector<int> key(V,INT_MAX);
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vector<int> parent(V,-1);
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vector<bool> mst(V,false);
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int ans=0;
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prims(adj,key,parent,mst,V,E,ans);
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cout<<ans<<endl;
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for(int i=1; i<V; i++){
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cout<<parent[i] << "-" << i << endl;
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}
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return 0;
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}
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