Three Hundred - Twenty-Nine Commit: Implement exist_edge() function

Author: AAdewunmi

Section_12(Graphs)/(1)_graph.py

@@ -55,4 +55,7 @@ def insert_edge(self, u, v, weight_edge = 1):
         self._adjacent_matrix[u][v] = weight_edge
 
     def remove_edge(self, u, v):
-        self._adjacent_matrix[u][v] = 0
+        self._adjacent_matrix[u][v] = 0
+
+    def exist_edge(self, u, v):
+        return self._adjacent_matrix[u][v] != 0