Cheapest Flights Within K Stops

#define pb push_back
class Solution {
    
     void solve(vector<vector<int>>& adj,vector<vector<int>>& cost,int src,int dst,int k,int& fare,int totCost,vector<bool>& visited)
    {
         if(k<-1)
             return;
         
         if(src == dst)
         {
             fare = min(fare, totCost);
             return;
         }
         
         visited[src]=true;
         for(int i=0;i<adj[src].size();i++)
         {
             if(!visited[adj[src][i]] and (totCost + cost[src][adj[src][i]]) <= fare)
                 solve(adj, cost, adj[src][i], dst, k-1, fare, totCost+cost[src][adj[src][i]], visited);
         }
         visited[src] = false;

    }
    
public:
   
    
    int findCheapestPrice(int n, vector<vector<int>>& flights, int src, int dst, int K) 
{
    ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout.tie(NULL);
            
        vector<vector<int>> adj(n);
        vector<vector<int>> cost(n+1, vector<int>(n+1));
        
        for(int i=0;i<flights.size();i++)
        {
            adj[flights[i][0]].pb(flights[i][1]);
            cost[flights[i][0]][flights[i][1]] = flights[i][2];
        }
        vector<bool> visited(n+1, false);
        int fare = INT_MAX;
        
        solve(adj, cost, src, dst, K, fare, 0 ,visited);
        
        if(fare == INT_MAX)
            return -1;
        return fare;
}
    
};