[강병호] Day13

leetcode2/1easy/강병호/Q94.py

@@ -0,0 +1,18 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+class Solution:
+    def inorderTraversal(self, root: Optional[TreeNode]) -> list[int]:
+        result, stack = [], []
+        curr = root
+        while curr or stack:
+            while curr:
+                stack.append(curr)
+                curr = curr.left
+            curr = stack.pop()
+            result.append(curr.val)
+            curr = curr.right
+        return result

leetcode2/2medium/강병호/Q200.py

@@ -0,0 +1,27 @@
+class Solution:
+    def numIslands(self, grid: list[list[str]]) -> int:
+        if not grid:
+            return 0
+
+        count = 0
+
+        def dfs(row, col):
+            if row < 0 or row >= len(grid) or col < 0 or col >= len(grid[0]) or grid[row][col] == '0':
+                return
+
+            grid[row][col] = '0'
+
+            dfs(row+1, col)
+            dfs(row, col+1)
+            dfs(row-1, col)
+            dfs(row, col-1)
+
+
+        for r in range(len(grid)):
+            for c in range(len(grid[0])):
+                if grid[r][c] == '1':
+                    dfs(r, c)
+                    count += 1
+
+
+        return count