BFS解法 732ms

lc200. Number of Islands.py

@@ -0,0 +1,47 @@
+import queue
+
+
+class Solution:
+    def numIslands(self, grid):
+        """
+        :type grid: List[List[str]]
+        :rtype: int
+        """
+        if not grid:
+            return 0
+        res = 0
+        length = len(grid)
+        length0 = len(grid[0])
+
+        q = queue.Queue()
+        visited = [[0] * length0 for i in range(length)]
+
+        for i in range(length):
+            for j in range(length0):
+                if not visited[i][j] and grid[i][j] == '1':
+                    q.put((i, j))
+                    res += 1
+                    while not q.empty():
+
+                        isl = q.get()
+                        if isl[0] < 0 or isl[0] >= length:
+                            continue
+                        if isl[1] < 0 or isl[1] >= length0:
+                            continue
+                        if not visited[isl[0]][isl[1]] and grid[isl[0]][isl[1]] == '1':
+                            visited[isl[0]][isl[1]] = 1
+                            q.put((isl[0] - 1, isl[1]))
+                            q.put((isl[0] + 1, isl[1]))
+                            q.put((isl[0], isl[1] - 1))
+                            q.put((isl[0], isl[1] + 1))
+        return res
+
+
+snum = '''11000
+11000
+00100
+00011'''
+slst = snum.split('\n')
+grid = [[int(x) for x in list(s)] for s in slst]
+soln = Solution()
+print(soln.numIslands(slst))