Merge pull request #884 from hlee2052/main

HyunWooLee/week9 - backtracking/2023-11-12-1593-split_a_string_into_max_number_of_unique_substrings.py

@@ -0,0 +1,21 @@
+class Solution:
+    def maxUniqueSplit(self, s: str) -> int:
+
+        def dfs(i):
+
+            res = 0
+
+            if i >= len(s):
+                return 0
+
+            for j in range(i + 1, len(s) + 1):
+                tmp = s[i:j]
+                if tmp not in visited:
+                    visited.add(tmp)
+                    res = max(res, 1 + dfs(j))
+                    visited.remove(tmp)
+
+            return res
+
+        visited = set()
+        return dfs(0)

HyunWooLee/week9 - backtracking/2023-11-12-77_Combinations.py

@@ -0,0 +1,20 @@
+class Solution:
+
+    def combine(self, n: int, k: int) -> List[List[int]]:
+
+        def dfs(start, arr):
+            if start > n + 1:
+                return
+
+            if len(arr) == k:
+                result.append(arr[:])
+                return
+
+            for i in range(start, n + 1):
+                arr.append(i)
+                dfs(i + 1, arr)
+                arr.pop()
+
+        result = []
+        dfs(1, [])
+        return result

HyunWooLee/week9 - backtracking/2023-11-12-79_word_search.py

@@ -0,0 +1,39 @@
+class Solution(object):
+    def exist(self, board, word):
+        """
+        :type board: List[List[str]]
+        :type word: str
+        :rtype: bool
+        """
+
+        def dfs(row, col, curr_len):
+            if row < 0 or len(board) <= row or col < 0 or len(board[0]) <= col:
+                return False
+
+            curr_word = word[len(word) - curr_len]
+
+            if board[row][col] != curr_word:
+                return False
+
+            if curr_len == 1:
+                return True
+
+            prev = board[row][col]
+
+            board[row][col] = None
+
+            top = dfs(row - 1, col, curr_len - 1)
+            down = dfs(row + 1, col, curr_len - 1)
+            left = dfs(row, col - 1, curr_len - 1)
+            right = dfs(row, col + 1, curr_len - 1)
+
+            board[row][col] = prev
+
+            return top or down or left or right
+
+        for i in range(len(board)):
+            for j in range(len(board[0])):
+                if dfs(i, j, len(word)):
+                    return True
+
+        return False