Add #0028 Find the Index of the First Occurrence in a String

Author: dgper13

#0028 Find the Index of the First Occurrence in a String.py

@@ -0,0 +1,32 @@
+class Solution:
+    def strStr(self, haystack: str, needle: str) -> int:
+        """
+        Implement strStr() function. Given two strings, return the index of the first occurrence 
+        of 'needle' in 'haystack', or -1 if 'needle' is not part of 'haystack'.
+
+        Parameters:
+        haystack (str): The main string to search within.
+        needle (str): The substring to search for.
+
+        Returns:
+        int: The index of the first occurrence of 'needle' in 'haystack', or -1 if not found.
+        """
+        
+        if len(haystack) < len(needle):
+            return -1  # If haystack is shorter than needle, needle cannot be found
+
+        i = 0  # Pointer for haystack
+        j = 0  # Pointer for needle
+        needle_length = len(needle)  # Length of the needle
+
+        while i < len(haystack):
+            if haystack[i] == needle[j]:
+                j += 1  # Move to the next character in needle
+                if j == needle_length:
+                    return i - j + 1  # Found the needle, return the start index
+                i += 1  # Move to the next character in haystack
+            else:
+                i = i - j + 1  # Reset haystack pointer to the next position after the last match
+                j = 0  # Reset needle pointer
+                
+        return -1  # Needle not found in haystack