0664. Strange Printer

https://leetcode.com/problems/strange-printer

Description

There is a strange printer with the following two special properties:

• The printer can only print a sequence of the same character each time.

• At each turn, the printer can print new characters starting from and ending at any place and will cover the original existing characters.

Given a string s, return the minimum number of turns the printer needed to print it.

Example 1:

**Input:** s = "aaabbb"
**Output:** 2
**Explanation:** Print "aaa" first and then print "bbb".

Example 2:

**Input:** s = "aba"
**Output:** 2
**Explanation:** Print "aaa" first and then print "b" from the second place of the string, which will cover the existing character 'a'.

Constraints:

• 1 <= s.length <= 100

• s consists of lowercase English letters.

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