16.md

Shortest Path in undirected graph

vector<int> shortestPath(vector<vector<int>>& edges, int n,int m, int src){
        // code here
        
        vector<int>adj[n];
        vector<int>visited(n,0);
        
         for(int i = 0; i<m; i++){
            int u = edges[i][0];
            int v = edges[i][1];
            
            adj[u].push_back(v);
            adj[v].push_back(u);
        }    
            
        queue<pair<int,int>>q;
        
        vector<int>ans(n,-1);
        
        ans[src]=0;
        q.push({src,0});
        visited[src]=1;
        
        while(!q.empty())
        {
            int node=q.front().first;
            int d=q.front().second;
            q.pop();
            
            for(auto it : adj[node])
            {
                if(visited[it]==0)
                {
                    visited[it]=1;
                    ans[it]=d+1;
                    q.push({it,d+1});
                }
            }
        }

            //  q.push(src);
            //  visited[src] = true;
        //  while(q.empty()==false){
            
        //    int u = q.front();
        //    q.pop();
           
        //    for(int e: adj[u]){
        //       if(visited[e] == false){
        //          res[e] = res[u] + 1;
        //          visited[e] = true;
        //          q.push(e);
        //       }     
        //    }
        
        // }
        
        return ans;
    }