[12/19] 1971. Find if Path Exists in Graph

from collections import defaultdict
class Solution:
    def validPath(self, n: int, edges: List[List[int]], source: int, destination: int) -> bool:

        graph = defaultdict(list)
        for n1, n2 in edges:
            graph[n1].append(n2)
            graph[n2].append(n1)

        visited = set()

        def dfs(node):
            visited.add(node)
            if node == destination:
                return True
            
            res = False
            for nxt in graph[node]:
                if nxt not in visited:
                    res = res or dfs(nxt)
            return res
        return dfs(source)

class Solution {
public:
  bool validPath(int n, vector<vector<int>>& edges, int source, int destination) {
    std::vector<std::vector<int>> graph(n, std::vector<int>());
    std::vector<bool> visited(n, 0);

    for (auto &v : edges) {
      graph[v[0]].push_back(v[1]);
      graph[v[1]].push_back(v[0]);
    }
    std::stack<int> st;
    st.push(source);
    while (!st.empty()) {
      int curr = st.top(); st.pop();
      if (curr == destination) {
        return true;
      }
      visited[curr] = true;
      for (auto &node : graph[curr]) {
        if (!visited[node]) {
          st.push(node);
        }
      }
    }
    return false;
  }
};