Count the paths

import java.util.*;

class Solution {
    public int countPaths(int[][] edges, int V, int src, int dest) {
        int[] dp = new int[V];
        ArrayList<Integer>[] graph = new ArrayList[V];
        for (int i = 0; i < V; i++) {
            graph[i] = new ArrayList<>();
            dp[i] = -1;
        }

        for (int i = 0; i < edges.length; i++)
            graph[edges[i][0]].add(edges[i][1]);

        return dfs(graph, dp, src, dest);
    }

    int dfs(ArrayList<Integer>[] graph, int dp[], int src, int dest) {
        if (src == dest)
            return 1;
        if (dp[src] != -1)
            return dp[src];

        int count = 0;
        for (int i = 0; i < graph[src].size(); i++)
            count += dfs(graph, dp, graph[src].get(i), dest);

        return dp[src] = count;
    }
}