From 0fbacd5d9b4c72db15f5f1ddae2c73b320a8c554 Mon Sep 17 00:00:00 2001
From: Camille0512 <lizx0512@connect.hku.hk>
Date: Sun, 27 Feb 2022 01:19:55 +0800
Subject: [PATCH] modified 151. Add 2 python versions. No need to implement
 Carlo's idea in such a complecated way by inviting extra space.

---
 problems/0151.翻转字符串里的单词.md | 32 ++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/problems/0151.翻转字符串里的单词.md b/problems/0151.翻转字符串里的单词.md
index ead5fa12..7588cbd6 100644
--- a/problems/0151.翻转字符串里的单词.md
+++ b/problems/0151.翻转字符串里的单词.md
@@ -438,6 +438,38 @@ class Solution:
 
 ```
 
+```python
+class Solution:
+    def reverseWords(self, s: str) -> str:
+        # method 1 - Rude but work & efficient method.
+        s_list = [i for i in s.split(" ") if len(i) > 0]
+        return " ".join(s_list[::-1])
+
+        # method 2 - Carlo's idea
+        def trim_head_tail_space(ss: str):
+            p = 0
+            while p < len(ss) and ss[p] == " ":
+                p += 1
+            return ss[p:]
+
+        # Trim the head and tail space
+        s = trim_head_tail_space(s)
+        s = trim_head_tail_space(s[::-1])[::-1]
+
+        pf, ps, s = 0, 0, s[::-1] # Reverse the string.
+        while pf < len(s):
+            if s[pf] == " ":
+                # Will not excede. Because we have clean the tail space.
+                if s[pf] == s[pf + 1]:
+                    s = s[:pf] + s[pf + 1:]
+                    continue
+                else:
+                    s = s[:ps] + s[ps: pf][::-1] + s[pf:]
+                    ps, pf = pf + 1, pf + 2
+            else:
+                pf += 1
+        return s[:ps] + s[ps:][::-1] # Must do the last step, because the last word is omit though the pointers are on the correct positions,
+```
 
 Go：