1055 solution updated

Partho Biswas · Partho Biswas · commit 897d950dac87 · 2019-11-10T22:41:09.000+06:00
diff --git a/README.md b/README.md
@@ -283,7 +283,7 @@ I have solved quite a number of problems from several topics. See the below tabl
 |06| [392. Is Subsequence](https://leetcode.com/problems/is-subsequence/)| [Python](leetcode.com/python/392_Is_Subsequence.py)| [Ex 1](https://leetcode.com/problems/is-subsequence/discuss/87264/Easy-to-understand-binary-search-solution), [Ex 3](https://leetcode.com/problems/is-subsequence/discuss/87302/Binary-search-solution-for-follow-up-with-detailed-comments/144323) | Easy | 📌  |
 |07| **[55. Jump Game](https://leetcode.com/problems/jump-game/)** | [Python](leetcode.com/python/55_Jump_Game.py)| **[Official](https://leetcode.com/articles/jump-game/)** , [Art 1](https://tinyurl.com/yy9vyjyn)| Medium | 📌 **Must Check. Learned a lot** |
 |08| [45. Jump Game II](https://leetcode.com/problems/jump-game-ii/)| [Python](leetcode.com/python/45_Jump_Game_II.py)| [Vid  1](https://www.youtube.com/watch?v=cETfFsSTGJI), [Vid 2](https://www.youtube.com/watch?v=jH_5ypQggWg), [Vid 3](https://www.youtube.com/watch?v=vBdo7wtwlXs), [Art 1](https://tinyurl.com/yalsno6r) | Hard | 📌  |
-|09| **[1055. Shortest Way to Form String](https://leetcode.com/problems/shortest-way-to-form-string/)**| [Python](leetcode.com/python/1055_Shortest_Way_to_Form_String.py)| [Art 1](https://tinyurl.com/t6xap4c), [Art 2](https://leetcode.com/problems/shortest-way-to-form-string/discuss/330938/Accept-is-not-enough-to-get-a-hire.-Interviewee-4-follow-up) | Medium | 📌 **Very informative** |
+|09| **[1055. Shortest Way to Form String](https://leetcode.com/problems/shortest-way-to-form-string/)**| [Python](leetcode.com/python/1055_Shortest_Way_to_Form_String.py)| [Art 1](https://tinyurl.com/t6xap4c), [Art 2](https://leetcode.com/problems/shortest-way-to-form-string/discuss/330938/Accept-is-not-enough-to-get-a-hire.-Interviewee-4-follow-up) | Medium | 📌 **[Check BS approach again](https://tinyurl.com/t6xap4c)** |
 
 
 ### [Dynamic Programming](https://www.educative.io/courses/grokking-dynamic-programming-patterns-for-coding-interviews)
diff --git a/leetcode.com/python/1055_Shortest_Way_to_Form_String.py b/leetcode.com/python/1055_Shortest_Way_to_Form_String.py
@@ -60,16 +60,18 @@ def shortestWay(self, source, target):
         sourceCharIndices = defaultdict(list)
         for idx, char in enumerate(source):
             sourceCharIndices[char].append(idx)
-        sourceIdx, subsequencesCount = 0, 0
+        sourceIdx, subsequencesCount = -1, 0
         for char in target:
             if char not in sourceCharIndices:
                 return -1
-            j = bisect.bisect_left(sourceCharIndices[char], sourceIdx)          # index in sourceCharIndices[char] that is >= sourceIdx
-            if j ==len(sourceCharIndices[char]):                                # wrap around to beginning of source
+            offsetListForChar = sourceCharIndices[char]
+            j = bisect.bisect_left(offsetListForChar, sourceIdx)          # index in sourceCharIndices[char] that is >= sourceIdx
+            if j == len(offsetListForChar):
                 subsequencesCount += 1
-                j = 0
-            sourceIdx = sourceCharIndices[char][j] + 1                          # next index in source
-        return subsequencesCount if sourceIdx == 0 else subsequencesCount + 1   # add 1 for partial source
+                sourceIdx = offsetListForChar[0] + 1
+            else:
+                sourceIdx = offsetListForChar[j] + 1
+        return subsequencesCount
 
 
 
@@ -79,7 +81,7 @@ def shortestWay(self, source, target):
 
 
 sol = Solution()
-source = "abc"
-target = "abcbc"
+source = "abcab"
+target = "aabbaac"
 out = sol.shortestWay(source, target)
 print('Res: ', out)
