Create Minimum Additions to Make Valid String.py

Author: erjan

Minimum Additions to Make Valid String.py

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+'''
+Given a string word to which you can insert letters "a", "b" or "c" anywhere and any number of times, return the minimum 
+number of letters that must be inserted so that word becomes valid.
+
+A string is called valid if it can be formed by concatenating the string "abc" several times.
+'''
+
+class Solution:
+    def addMinimum(self, word: str) -> int:
+        it = 0
+        result = 0
+        while it < len(word) :
+            if word[it:it+3] == "abc":
+                it += 3  
+            elif word[it:it+2] in ["ab","ac","bc"]:
+                result += 1
+                it += 2
+            else:
+                result += 2
+                it += 1
+        return result
+