add longest-increasing-subsequence, spiral-matrix

Author: i-mprovising

design-add-and-search-words-data-structure/i-mprovising.py

@@ -30,7 +30,7 @@ def dfs(self, start, word):
         ch = word[0]
         if ch == word:
             if ch == '.':
-                return any([node.end for c, node in start.children.items()])
+                return any([node.end for node in start.children.values()])
             elif ch in start.children:
                 if start.children[ch].end:
                     return True

longest-increasing-subsequence/i-mprovising.py

@@ -0,0 +1,29 @@
+"""
+Time complexity O(n^2)
+Space complexity O(n)
+
+Dynamic programming
+"""
+
+class Solution:
+    def lengthOfLIS(self, nums: List[int]) -> int:
+        
+        dp = [(1, nums[0])] # sequence len, max num in sequence
+
+        for i in range(1, len(nums)):
+            num = nums[i]
+            max_len = 1
+            for j in range(i):
+                x, y = dp[j]
+                if y < num:
+                    if max_len < x + 1:
+                        max_len = x + 1
+            dp.append((max_len, num))
+
+        # find max len
+        max_len = 0
+        for x in dp:
+            if x[0] > max_len:
+                max_len = x[0]
+
+        return max_len

spiral-matrix/i-mprovising.py

@@ -0,0 +1,60 @@
+"""
+Time complexity O(m*n)
+
+단순구현
+"""
+
+class Solution:
+    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
+        """
+        111  
+        1M1   visited
+        111 
+        """
+        m, n = len(matrix), len(matrix[0])
+        
+        board = [[0] * (n+2)]
+        for i in range(m):
+            tmp = [0] + matrix[i] + [0]
+            board.append(tmp)
+        board.append([0] * (n+2))
+
+        visited = [[True] * (n+1)]
+        for _ in range(m):
+            tmp = [True] + [False] * n + [True]
+            visited.append(tmp)
+        visited.append([True] * (n+1))
+
+        direction = 0
+        x, y = 1, 1
+        numbers = []
+
+        for _ in range(m * n):
+            numbers.append(board[x][y])
+            visited[x][y] = True
+
+            i, j = self.next_idx(direction, x, y)
+            if visited[i][j]:
+                direction = self.change_dir(direction)
+                x, y = self.next_idx(direction, x, y)
+            else:
+                x, y = i, j
+
+        return numbers
+
+    def next_idx(self, dir, x, y):
+        """
+        0 1 2 3 : R D L U
+        """
+        if dir == 0:
+            y += 1
+        elif dir == 1:
+            x += 1
+        elif dir == 2:
+            y -= 1
+        else:
+            x -= 1
+        return x, y
+    
+    def change_dir(self, dir):
+        return (dir + 1) % 4