Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.
Count the number of distinct islands. An island is considered to be the same as another if and only if one island can be translated (and not rotated or reflected) to equal the other.
Example 1:
11000 11000 00011 00011Given the above grid map, return
1.
Example 2:
11011 10000 00001 11011Given the above grid map, return
3.Notice that:
11 1and
1 11are considered different island shapes, because we do not consider reflection / rotation.
Note:
The length of each dimension in the given grid does not exceed 50.
[Depth-First Search] [Breadth-First Search] [Union Find] [Hash Table] [Hash Function]
- Number of Islands (Medium)
- Number of Distinct Islands II (Hard)