Added doctests for matrix/count_islands_in_matrix.py

matrix/count_islands_in_matrix.py

@@ -4,12 +4,45 @@
 
 
 class Matrix:  # Public class to implement a graph
-    def __init__(self, row: int, col: int, graph: list[list[bool]]) -> None:
-        self.ROW = row
-        self.COL = col
+    def __init__(self, graph: list[list[bool]]) -> None:
+        """
+        Initialise matrix with number of rows, columns, and graph.
+
+        >>> m = Matrix([[True, False, False, False],
+        ...              [True, False, True, False],
+        ...              [False, False, True, True]])
+        >>> m.ROW
+        3
+        >>> m.COL
+        4
+        >>> m.graph
+        [[True, False, False, False],
+         [True, False, True, False],
+         [False, False, True, True]]
+        """
         self.graph = graph
+        self.ROW = len(graph)
+        self.COL = len(graph[0])
 
     def is_safe(self, i: int, j: int, visited: list[list[bool]]) -> bool:
+        """
+        Checks if the cell (i, j) can be visited.
+
+        >>> visited = [[False, False, False],
+        ...             [False, False, False],
+        ...             [False, False, False]]
+        >>> m = Matrix([[True, False, False],
+        ...              [False, False, True],
+        ...              [False, False, True]])
+        >>> m.is_safe(0, 0, visited)
+        True
+        >>> m.is_safe(0, 2, visited)
+        False
+        >>> m.is_safe(-1, 2, visited)
+        False
+        >>> m.is_safe(1, 5, visited)
+        False
+        """
         return (
             0 <= i < self.ROW
             and 0 <= j < self.COL
@@ -18,15 +51,43 @@ def is_safe(self, i: int, j: int, visited: list[list[bool]]) -> bool:
         )
 
     def diffs(self, i: int, j: int, visited: list[list[bool]]) -> None:
-        # Checking all 8 elements surrounding nth element
+        """
+        Checking all 8 elements surrounding nth element.
+
+        >>> visited = [[False, False, False],
+        ...             [False, False, False],
+        ...             [False, False, False]]
+        >>> m = Matrix([[True, True, False],
+        ...              [False, True, False],
+        ...              [True, False, True]])
+        >>> m.diffs(0, 0, visited)
+        >>> visited
+        [[True, True, False],
+         [False, True, False],
+         [True, False, True]]
+        """
         row_nbr = [-1, -1, -1, 0, 0, 1, 1, 1]  # Coordinate order
         col_nbr = [-1, 0, 1, -1, 1, -1, 0, 1]
         visited[i][j] = True  # Make those cells visited
         for k in range(8):
             if self.is_safe(i + row_nbr[k], j + col_nbr[k], visited):
                 self.diffs(i + row_nbr[k], j + col_nbr[k], visited)
 
-    def count_islands(self) -> int:  # And finally, count all islands.
+    def count_islands(self) -> int:
+        """
+        Counts the number of islands in the matrix.
+
+        >>> m = Matrix([[True, True, False, False],
+        ...              [False, True, False, True],
+        ...              [True, False, False, True]])
+        >>> m.count_islands()
+        2
+        >>> m2 = Matrix([[True, True, False],
+        ...               [True, False, False],
+        ...               [False, False, True]])
+        >>> m2.count_islands()
+        2
+        """
         visited = [[False for j in range(self.COL)] for i in range(self.ROW)]
         count = 0
         for i in range(self.ROW):