387 solved using dictionary

387_first_unique_char.py

+# -*- coding: utf-8 -*-
+"""
+Created on Sun Apr 17 12:08:03 2022
+
+@author: johnb aka John Bedingfield
+"""
+
+# this is for LeetCode #387, FIrst Unique Character in a String
+# this was accepted
+# runtime: 129 ms, faster than 68.27% of python3 submissions
+# memory: 14.2MB, less than 20.47% of python3 submissions
+
+class Solution:
+    def firstUniqChar(self, s: str) -> int:
+        counts = {}         # dictionary to hold a count of each letter
+        
+        # loop throught the string and get a count of each letter
+        for c in s:
+            if c not in counts:
+                counts[c] = 1
+            else:
+                counts[c] = counts[c] + 1
+        #print(counts)
+        
+        # loop through the string and determine which char only has a count of 1
+        index = 0
+        for c in s:
+            if counts[c] == 1:
+                return index
+            else:
+                index += 1
+        # if we made it through with no answer, 
+        return -1
+    
+    
+if __name__ == "__main__":
+    s = "leetcode"
+    s2 = "loveleetcode"
+    s3 = "aabb"
+    
+    myS = Solution()
+    starttime = int(time())
+    print(myS.firstUniqChar(s3))
+    endtime = int(time())
+    totalTime = endtime - starttime
+    print(f"Total time was {totalTime}")