- Word Break #271

Author: ayosecu

word-break/ayosecu.py

@@ -0,0 +1,35 @@
+from typing import List
+
+class Solution:
+    """
+        - Time Complexity: O(n^2), n = len(s)
+        - Space Complexity: O(n + m)
+            - n = len(s) = dp size
+            - m = The number of characters in wordDict (wordDict size)
+    """
+    def wordBreak(self, s: str, wordDict: List[str]) -> bool:
+        n = len(s)
+        wordDict = set(wordDict)
+
+        # Use DP: dp[i] => s[0:i] is possible to be seperated by dictionary words
+        dp = [False] * (n + 1)
+        dp[0] = True
+
+        for i in range(1, n + 1):
+            for j in range(i):
+                if dp[j] and s[j:i] in wordDict:
+                    dp[i] = True
+                    break   # s[i-1] is possible => don't need to check forward string
+        
+        return dp[-1]   # check s[0:n]
+
+tc = [
+        ("leetcode", ["leet","code"], True),
+        ("applepenapple", ["apple","pen"], True),
+        ("catsandog", ["cats","dog","sand","and","cat"], False)
+]
+
+sol = Solution()
+for i, (s, wordDict, e) in enumerate(tc, 1):
+    r = sol.wordBreak(s, wordDict)
+    print(f"TC {i} is Passed!" if r == e else f"TC {i} is Failed! - Expected: {e}, Result: {r}")