PatternOptimizer | Topcoder Archive

Problem Statement

Some dictionaries use a word pattern that consists of letters, '?' symbols which each denote exactly one letter, and '*' symbols which each denote zero or more letters.

Interestingly, some patterns represent the same set of words. For example, "*??*a" and "?*?a" (quotes for clarity only) patterns both represent all words that consist of three or more letters and end with 'a'.

You will be given a String pattern. Your method should return the shortest pattern that represents the same set of words as the given pattern. Return the lexicographically first in case of tie.

Definition

Class:: PatternOptimizer
Method:: optimize
Parameters:: String
Returns:: String
Method signature:: String optimize(String pattern)
(be sure your method is public)

Notes

Note that '*' comes before '?' in the lexicographical order.

Constraints

pattern will contain between 1 and 50 characters, inclusive.
pattern will contain only letters ('a'-'z', 'A'-'Z'), '?' and '*'.

Examples

```
"*??*a"
```
```
Returns: "*??a"
```
```
"*b**a*"
```
```
Returns: "*b*a*"
```
```
"cla??"
```
```
Returns: "cla??"
```
```
"*?*?*?*"
```
```
Returns: "*???"
```
```
"T***nd?*"
```
```
Returns: "T*nd*?"
```

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