Shortest path in Undirected Graph

 vector<int> shortestPath(vector<vector<int>>& edges, int N,int M, int src){
        vector<vector<int>>adj(N+1); //creating a adjacency list

        for(auto &x:edges) //creating a undirected graph
        {
            adj[x[0]].push_back(x[1]);
            adj[x[1]].push_back(x[0]);
        }
        queue<int>pq; //creating a queue
        pq.push(src);
         vector<int>dist(N,INT_MAX); //caluculating distance matrix with INT_MAX as initial
        dist[src]=0;
        while(!pq.empty())
        {
            int node=pq.front();
            pq.pop();
            for(auto &x:adj[node])
            {
                if(dist[x]>dist[node]+1) //updating distances
                {
                    dist[x]=dist[node]+1;
                    pq.push(x);
                }
            }
        }
        if(auto &x:dist)
        {
            if(x==INT_MAX)
            {
                X=-1; //node is unreachable
            }
            
        }
        return dist;
    }