Create DFS.cpp

Graph/DFS_DepthFirstSearch/DFS.cpp

@@ -0,0 +1,55 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+vector<vector<int>> adj;
+vector<bool> visited;
+void dfs(int from) {
+	cout << endl << "--dfs(" << from << ") is called--" << endl;
+	cout << "   so visited " << from <<" will be 'true'" << endl;
+	visited[from] = true;
+	for (size_t i = 0; i < adj[from].size(); ++i) {
+		int to = adj[from][i];
+		cout << "   from : "<<from<<"/ to : " << to << endl;
+		if (!visited[to]) {
+			cout << "   dfs(" << to << ") is called" << endl;
+			dfs(to);
+		}
+	}
+}
+
+void dfsAll() {
+	visited = vector<bool>(adj.size(), false);
+	for (size_t i = 0; i < adj.size(); ++i) {
+		if (!visited[i]) {
+			cout << endl << "-dfsAll(" << i << ") is called-" << endl;
+			dfs(i);
+		}
+		else {
+			cout << "node " << i << " is already visited" << endl;
+		}
+	}
+}
+
+void showAdj(vector<vector<int>> adjacent) {
+	for (size_t i = 0; i < adjacent.size(); ++i) {
+		for (size_t j = 0; j < adj[i].size(); ++j) {
+			if (adjacent[i][j] != NULL)
+			{
+				cout << i << " -> " << adjacent[i][j] << endl;
+			}
+		}
+	}
+}
+int main() {
+	adj.resize(7);
+	visited.resize(7);
+	adj[0].push_back(1);
+	adj[0].push_back(2);
+	adj[1].push_back(3);
+	adj[1].push_back(4);
+	adj[5].push_back(6);
+	showAdj(adj);
+	dfsAll();
+	return 0;
+}