Squash commit

utilities/graph_dfs.py

@@ -0,0 +1,24 @@
+def graph_dfs(matrix):
+    rows, cols = len(matrix), len(matrix[0])
+    visited = set()
+    directions = ((0, 1), (0, -1), (1, 0), (-1, 0))
+    def dfs(i, j):
+        if (i, j) in visited:
+            return
+        visited.add((i, j))
+        # Traverse neighbors.
+        for direction in directions:
+            next_i, next_j = i + direction[0], j + direction[1]
+            if 0 <= next_i < rows and 0 <= next_j < cols: # Check boundary.
+                # Add any other checking here ^
+                dfs(next_i, next_j)
+
+    for i in range(rows):
+        for j in range(cols):
+            dfs(i, j)
+
+graph_dfs([
+    [1, 2, 3, 4],
+    [5, 6, 7, 8],
+    [9, 10, 11, 12],
+])