https://codeiq.jp/ace/joboffer_apli/q377

island_count.py

#coding: utf-8

#python 2.7

class island_count:
    def __init__(self, pattern = None):
        self.pattern = None
        if pattern:
            self.load(pattern)

    def load(self, pattern):
        self.pattern = [list(linedata) for linedata in pattern.splitlines()]

        #for items in self.pattern:
        #    print " ".join(items)

        w_max = max(map(len, self.pattern))
        w_min = min(map(len, self.pattern))
        if w_max != w_min:
            raise "invalid width"

        self.width = w_max
        self.height = len(self.pattern)

    def count(self):
        if not self.pattern:
            return -1

        already_read = set()
        def step(x, y):
            if (x,y) in already_read:
                return False

            if self.pattern[y][x] == u"●":
                already_read.add((x,y))
                if x > 0:
                    step(x - 1, y)
                if y > 0:
                    step(x, y - 1)
                if x < self.width - 1:
                    step(x + 1, y)
                if x > self.height - 1:
                    step(x, y + 1)
                return True
            else:
                return False

        c = 0
        for y in xrange(self.height):
            for x in xrange(self.width):
                if step(x,y):
                    c += 1
        return c

def main():
    pattern = u"""○○○○○○
○●●○○○
○○○○○○
○○○○●○
○○○●○○
○○○○○○
"""

    island = island_count()
    island.load(pattern)
    print island.count()


if __name__ == "__main__":
    main()