GraphMatrixDFSUnion Find
A grid contains 1s (land) and 0s (water). An island is a group of land cells connected horizontally or vertically. Count the islands.
Input
Line 1: r and c. Next r lines: a string of c characters, each 0 or 1 (no spaces).
Output
Print the number of islands.
Constraints
1 <= r, c <= 50
Example 1
Input
4 5 11000 11000 00100 00011
Output
3
Three separate groups of land.