Create needle-in-haystack.py

Finds substring needle in haystack

needle-in-haystack.py

@@ -0,0 +1,14 @@
+class Solution:
+    def strStr(self, haystack: str, needle: str) -> int:
+        rpointer = 0
+        if len(needle) > len(haystack):
+            return -1
+        for lpointer in range(len(haystack)):
+            rpointer = lpointer
+            while haystack[rpointer] == needle[rpointer-lpointer]:
+                rpointer += 1
+                if rpointer-lpointer > len(needle) - 1:
+                    return lpointer
+                if rpointer > len(haystack) - 1:
+                    return -1
+        return -1