```
public class Solution
extends Object
```
38 - Count and Say\. Medium The **count-and-say** sequence is a sequence of digit strings defined by the recursive formula: * `countAndSay(1) = "1"` * `countAndSay(n)` is the way you would "say" the digit string from `countAndSay(n-1)`, which is then converted into a different digit string. To determine how you "say" a digit string, split it into the **minimal** number of groups so that each group is a contiguous section all of the **same character.** Then for each group, say the number of characters, then say the character. To convert the saying into a digit string, replace the counts with a number and concatenate every saying. For example, the saying and conversion for digit string `"3322251"`: ![](https://assets.leetcode.com/uploads/2020/10/23/countandsay.jpg) Given a positive integer `n`, return _the_ `nth` _term of the **count-and-say** sequence_. **Example 1:** **Input:** n = 1 **Output:** "1" **Explanation:** This is the base case. **Example 2:** **Input:** n = 4 **Output:** "1211" **Explanation:** countAndSay(1) = "1" countAndSay(2) = say "1" = one 1 = "11" countAndSay(3) = say "11" = two 1's = "21" countAndSay(4) = say "21" = one 2 + one 1 = "12" + "11" = "1211" **Constraints:** * `1 <= n <= 30`

Class Solution