Implemented unweighted graph with BFS and DFS algorithms

Author: KyattPL

data-structures/Graph.py

@@ -0,0 +1,69 @@
+class Graph:
+    def __init__(self):
+        self.path = []
+        self.vertices = []
+        self.neighbors = []
+
+    def add_node(self, number, neighbors):
+        self.vertices.append(number)
+        self.neighbors.append(neighbors)
+        self.path.append(0)
+
+    # 0 - white, 1 - grey, 2 - black
+    def BFS(self, start):
+        color = [0] * len(self.vertices)
+        distance = [0] * len(self.vertices)
+        queue = []
+        for vert in self.vertices:
+            if vert != start:
+                color[vert] = 0
+                self.path[vert] = None
+        color[start] = 1
+        distance[start] = 0
+        self.path[start] = None
+        queue.append(start)
+        while len(queue) != 0:
+            u = queue.pop(0)
+            for vert in self.neighbors[u]:
+                if color[vert] == 0:
+                    color[vert] = 1
+                    distance[vert] = distance[u] + 1
+                    self.path[vert] = u
+                    queue.append(vert)
+            color[u] = 2
+
+    def DFS(self, start):
+        visited = [False] * (len(self.vertices))
+        self.DFS_move(start, visited)
+
+    def DFS_move(self, vert, visited):
+        visited[vert] = True
+        print(vert, end=' ')
+
+        for adj in self.neighbors[vert]:
+            if visited[adj] == False:
+                self.DFS_move(adj, visited)
+
+    def print_path(self, start, end):
+        if start == end:
+            print(start)
+        elif self.path[end] == None:
+            print("Path from " + str(start) + " to " +
+                  str(end) + " doesn't exist!")
+        else:
+            self.print_path(start, self.path[end])
+            print(str(end) + " ")
+
+
+if __name__ == "__main__":
+    g = Graph()
+    g.add_node(0, [1])
+    g.add_node(1, [0, 2, 3])
+    g.add_node(2, [1, 3, 5])
+    g.add_node(3, [1, 2, 4])
+    g.add_node(4, [3, 5])
+    g.add_node(5, [2, 4, 6])
+    g.add_node(6, [5])
+    g.BFS(0)
+    g.print_path(0, 6)
+    g.DFS(4)