Untitled

class Solution {
public:
    double bfs(unordered_map<string,vector<pair<string,double>>>&adj,string src,string tar){
        if(adj.find(src) ==adj.end() || adj.find(tar) ==adj.end()) return -1.0;
        queue<pair<string,double>> q; //current node,product
        unordered_set<string> vis;
        q.push({src,1.0});
        vis.insert(src);
        while(!q.empty()){
            pair<string,double> p=q.front();
            q.pop();
            string node=p.first;
            double dist=p.second;
            if(node==tar) return dist;

            for(auto nbr:adj[node]){
                if(vis.find(nbr.first)==vis.end()){
                    q.push({nbr.first,dist * nbr.second});
                    vis.insert(nbr.first);
                }
            }
        }
        return -1.0;
    }

    vector<double> calcEquation(vector<vector<string>>& eq, vector<double>& values, vector<vector<string>>& que) {
        //making adjlist
        unordered_map<string,vector<pair<string,double>>> adj;
        for(int i=0;i<eq.size();i++){
            string a=eq[i][0];
            string b=eq[i][1];
            adj[a].push_back({b,values[i]});
            adj[b].push_back({a,1/values[i]});
        }
        vector<double> ans;
        for(auto i:que){
            double x=bfs(adj,i[0],i[1]);
            ans.push_back(x);
        }
        return ans;
    }
};