Added dfs algorithm (iterative version)

Author: dosart

.gitignore

@@ -6,3 +6,4 @@ dist/
 .coverage
 coverage.xml
 .pytest_cache/
+.vs/

algoritms/dfs_iterative.py

@@ -0,0 +1,24 @@
+"""Implementation iterative depth-first search."""
+
+
+def dfs_iterative(graph):
+    """Visit all the vertex of graph.
+
+    Args:
+        graph: graph for search
+
+    Returns:
+        visited (dict): key (vertex id), value (true if vetrex is visited)
+    """
+    visited = {vertex : False for vertex in graph}
+
+    stack = []
+    for vertex in graph:
+        stack.append(vertex)
+
+    while len(stack) > 0:
+        vertex = stack.pop()
+        for adjacent_vertex in vertex:
+            if visited[adjacent_vertex] is False:
+                  stack.append(adjacent_vertex)
+                  visited[adjacent_vertex] == True