Fix DFS algorithm

Author: vadyushkins

algorithms/dfs/dfs.cpp

@@ -3,10 +3,10 @@
 std::vector<bool> &dfs(
  const std::vector<std::vector<int64_t>> &graph,
  std::vector<bool> &reachable,
- int node
+ int64_t node
 ) {
  reachable[node] = true;
- for (int neighbour : graph[node]) {
+ for (int64_t neighbour : graph[node]) {
  if (false == reachable[neighbour]) {
  dfs(graph, reachable, neighbour);
  }

algorithms/dfs/dfs.hpp

@@ -4,5 +4,5 @@
 std::vector<bool> &dfs(
  const std::vector<std::vector<int64_t>> &graph,
  std::vector<bool> &reachable,
- int node
+ int64_t node
 );