# 1844. Replace All Digits with Characters

https://leetcode.com/problems/replace-all-digits-with-characters

## Description

You are given a **0-indexed** string `s` that has lowercase English letters in its **even** indices and digits in its **odd** indices.

There is a function `shift(c, x)`, where `c` is a character and `x` is a digit, that returns the `xth` character after `c`.

* For example, `shift('a', 5) = 'f'` and `shift('x', 0) = 'x'`.

For every **odd** index `i`, you want to replace the digit `s[i]` with `shift(s[i-1], s[i])`.

Return `s` _after replacing all digits. It is **guaranteed** that_ `shift(s[i-1], s[i])` _will never exceed_ `'z'`.

**Example 1:**

```
**Input:** s = "a1c1e1"
**Output:** "abcdef"
**Explanation:** The digits are replaced as follows:
- s[1] -> shift('a',1) = 'b'
- s[3] -> shift('c',1) = 'd'
- s[5] -> shift('e',1) = 'f'
```

**Example 2:**

```
**Input:** s = "a1b2c3d4e"
**Output:** "abbdcfdhe"
**Explanation:** The digits are replaced as follows:
- s[1] -> shift('a',1) = 'b'
- s[3] -> shift('b',2) = 'd'
- s[5] -> shift('c',3) = 'f'
- s[7] -> shift('d',4) = 'h'
```

**Constraints:**

* `1 <= s.length <= 100`
* `s` consists only of lowercase English letters and digits.
* `shift(s[i-1], s[i]) <= 'z'` for all **odd** indices `i`.

## ac

```java
```
