50 lines
1.0 KiB
C++
50 lines
1.0 KiB
C++
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//dfs traversal of undirected graph using recursive approach
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#include <bits/stdc++.h>
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using namespace std;
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void dfs(vector<vector<int>>&adj, vector<int>&v,int x)
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{
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v[x]=1;
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cout<<x<<" ";//print the vertex visited
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for(int i=0;i<adj[x].size();i++)
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{
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if(v[adj[x][i]]==0)
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{
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dfs(adj,v,adj[x][i]);//call the dfs function if a node is not visited
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}
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}
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}
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int main()
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{
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int n,m;
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cin>>n>>m;//enter the number of vertices and number of edges
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vector<vector<int>>adj(n+1,vector<int>());
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//create an adjacency list according to the edges given in input
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for(int i=0;i<m;i++)
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{
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int u,v;
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cin>>u>>v;
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adj[u].push_back(v);
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adj[v].push_back(u);
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}
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cout<<"The dfs traversal is \n";
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vector<int>v(n+1,0);
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dfs(adj,v,1);
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return 0;
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}
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//INPUT
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//6 5
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//1 2
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//2 6
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//1 3
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//3 4
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//3 5
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//OUTPUT
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//The dfs traversal is
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//1 2 6 3 4 5
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//TIME COMPLEXITY OF THE PROGRAM
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//O(V+E)
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//where V is number of vertices
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//and E is number of edges
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