Rename dfs to depth_first_search.:

graph/depth_first_search_with_stack.cpp

@@ -0,0 +1,46 @@
+#include <iostream>
+#include <list>
+#include <vector>
+#include <stack>
+
+constexpr int WHITE = 0;
+constexpr int GREY = 1;
+constexpr int BLACK = 2;
+constexpr int INF = 99999;
+
+void dfs(const std::vector< std::list<int> > &graph, int start) {
+    std::vector<int> checked(graph.size(), WHITE);
+    checked[start] = GREY;
+    std::stack<int> stack;
+    stack.push(start);
+    while (!stack.empty()) {
+        int act = stack.top();
+        stack.pop();
+
+        if (checked[act] == GREY) {
+            std::cout << act << ' ';
+            for (auto it : graph[act]) {
+                stack.push(it);
+                if (checked[it] != BLACK) {
+                    checked[it] = GREY;
+                }
+            }
+            checked[act] = BLACK;  // nodo controllato
+        }
+    }
+}
+
+int main() {
+    int n = 0;
+    std::cin >> n;
+    std::vector< std::list<int> > graph(INF);
+    for (int i = 0; i < n; ++i) {
+        int u = 0, w = 0;
+        std::cin >> u >> w;
+        graph[u].push_back(w);
+    }
+
+    dfs(graph, 0);
+
+    return 0;
+}