LeetCode: 557 solved

Author: devMEremenko

Python/LeetCode/557. Reverse Words in a String III.py

@@ -1,5 +1,52 @@
 # https://leetcode.com/problems/reverse-words-in-a-string-iii/
 
 class Solution:
-    def reverseWords(self, s: str) -> str:        
-        return ' '.join([v[::-1] for v in s.split()])
+    def reverseWords(self, s: str) -> str:
+        # return self.solution1(s)
+        # return self.solution3(s)
+        return self.solution2(s)        
+        
+    # Time O(n), Space O(n)
+    def solution2(self, s):
+        res = []
+        word = []
+        
+        for char in s:
+            if char == ' ':
+                res.extend(reversed(word))
+                res.append(' ')
+                word = []
+            else:
+                word.append(char)
+        
+        res.extend(reversed(word))
+            
+        return ''.join(res)
+    
+    
+    # Time O(n), Space O(n)
+    def solution1(self, s):
+        if len(s) <= 1:
+            return s
+        
+        counter = 0
+        res = []
+        
+        def extract_word(from_index, count):
+            for prev in range(count):
+                res.append(s[from_index - prev])
+        
+        for idx, char in enumerate(s):
+            if char == ' ':
+                extract_word(idx - 1, counter)
+                res.append(' ')
+                counter = 0
+            else:
+                counter += 1
+                
+        extract_word(len(s) - 1, counter)
+                
+        return ''.join(res)
+    
+    def solution3(self, s):
+        return ' '.join([v[::-1] for v in s.split()])