Added reverse words solutions with two-pointer and reverse traversal methods

Author: Kondareddy1209

Leetcode/leetcode_151.py

@@ -0,0 +1,58 @@
+# Reverse Words in a String
+# Problem: Given a string, reverse the order of words.
+
+# ------------------------------------------------
+# Solution 1: Two Pointer Swap Method
+# ------------------------------------------------
+
+class SolutionSwap:
+    def reverseWords(self, s: str) -> str:
+        # split() removes extra spaces and converts string into list
+        # Example: "  hello world  " -> ['hello','world']
+        n = s.split()
+
+        # initialize two pointers
+        l = 0
+        r = len(n) - 1
+
+        # swap words until pointers meet
+        while l < r:
+            n[l], n[r] = n[r], n[l]
+            l += 1
+            r -= 1
+
+        # convert list back to string
+        return " ".join(n)
+
+
+# ------------------------------------------------
+# Solution 2: Reverse Traversal Method
+# ------------------------------------------------
+
+class SolutionLoop:
+    def reverseWords(self, s: str) -> str:
+        # convert string to list of words
+        n = s.split()
+
+        # empty string to store result
+        res = ""
+
+        # traverse from last word to first word
+        for i in range(len(n)-1, -1, -1):
+            res += n[i]
+
+            # add space between words
+            if i != 0:
+                res += " "
+
+        return res
+
+
+# ------------------------------------------------
+# Example Test
+# ------------------------------------------------
+
+s = "  hello world  "
+
+print("Swap Method:", SolutionSwap().reverseWords(s))
+print("Loop Method:", SolutionLoop().reverseWords(s))