depth first search added

algorithms/8_depth_first_search/dfs.py

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+# function for depth first search
+def dfs(data, start, visited=set()):
+
+    # if not visited print it
+    if start not in visited:
+        print(start, end=" ")
+
+    visited.add(start)
+
+    for i in data[start] - visited:
+
+        # if not visited gi in depth of it
+        dfs(data, i, visited)
+    return
+
+
+# sample data in dictionary form
+data = {
+        'A': {'B'},
+        'B': {'A', 'C', 'D'},
+        'C': {'B', 'E'},
+        'D': {'B', 'E'},
+        'E': {'C', 'D', 'F'},
+        'F': {'E'}
+        }
+
+
+if __name__ == '__main__':
+
+    dfs(data, 'A')

algorithms/8_depth_first_search/dfs_exercise.py

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+# function for depth first search
+def find_employees(data, start, employee, visited=set()):
+    # if not visited print it
+    if start not in visited:
+        print(start, end=" ")
+        if start == employee:
+            print(":", end=" ")
+    visited.add(start)
+
+    for i in data[start] - visited:
+        # if not visited go in depth of it
+        find_employees(data, i, visited)
+    return
+
+
+# sample data in dictionary form
+data = {
+    "karan": {"darshan", "nikhil"},
+    "darshan": {"khantil", "tanuj"},
+    "tanuj": {"nikhil"},
+    "krinish": {"hetul"},
+    "khantil": set(),
+    "nikhil": set()
+}
+
+
+if __name__ == '__main__':
+
+    find_employees(data, "karan", "karan")

algorithms/8_depth_first_search/dfs_exerscise.md

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+# DFS Exercise
+
+![Overview : Employee hierarchy](https://github.com/beladiyadarshan/DFS/blob/main/emp.png?raw=true)
+
+Given a graph containing managers and their employees as a dictionary of sets, print all employees reporting to a given manager.
+
+```
+data = {
+        "karan": {"darshan","nikhil"},
+        "darshan": {"khantil", "tanuj"},
+        "tanuj": {"nikhil"},
+        "krinish": {"hetul"},
+        "khantil" : set(),
+        "nikhil" : set()
+ }
+
+
+ ```
+
+ Example: Darshan and Nikhil are reporting to Karan. Khantil and Tanuj are reporting to Darshan.
+
+ ```
+ Q. Find all employees who are reporting to Karan.
+ ```
+
+**Explanation:**
+
+-So here, we want to find all the children nodes of Karan.
+
+-We will perform DFS starting on Karan and then traverse all the children of Karan which are unvisited. 
+
+**Output:**
+
+karan : nikhil darshan tanuj khantil 
+
+[Solution](https://github.com/beladiyadarshan/DFS/blob/main/dfs_exercise.py)