2129. Capitalize the Title

You are given a string `title` consisting of one or more words separated by a single space, where each word consists of English letters. Capitalize the string by changing the capitalization of each word such that:

• If the length of the word is `1` or `2` letters, change all letters to lowercase.
• Otherwise, change the first letter to uppercase and the remaining letters to lowercase.

Return the capitalized `title`.

Example 1:

```Input: title = "capiTalIze tHe titLe"
Output: "Capitalize The Title"
Explanation:
Since all the words have a length of at least 3, the first letter of each word is uppercase, and the remaining letters are lowercase.
```

Example 2:

```Input: title = "First leTTeR of EACH Word"
Output: "First Letter of Each Word"
Explanation:
The word "of" has length 2, so it is all lowercase.
The remaining words have a length of at least 3, so the first letter of each remaining word is uppercase, and the remaining letters are lowercase.
```

Example 3:

```Input: title = "i lOve leetcode"
Output: "i Love Leetcode"
Explanation:
The word "i" has length 1, so it is lowercase.
The remaining words have a length of at least 3, so the first letter of each remaining word is uppercase, and the remaining letters are lowercase.
```

Constraints:

• `1 <= title.length <= 100`
• `title` consists of words separated by a single space without any leading or trailing spaces.
• Each word consists of uppercase and lowercase English letters and is non-empty.

2129. Capitalize the Title
``````struct Solution;

impl Solution {
fn capitalize_title(title: String) -> String {
let words: Vec<String> = title
.split_whitespace()
.map(Solution::capitalize_word)
.collect();
words.join(" ")
}

fn capitalize_word(s: &str) -> String {
let n = s.len();
let mut res = "".to_string();
for (i, c) in s.char_indices() {
if i == 0 {
if n <= 2 {
res.push(c.to_ascii_lowercase());
} else {
res.push(c.to_ascii_uppercase());
}
} else {
res.push(c.to_ascii_lowercase());
}
}
res
}
}

#[test]
fn test() {
let title = "capiTalIze tHe titLe".to_string();
let res = "Capitalize The Title".to_string();
assert_eq!(Solution::capitalize_title(title), res);
let title = "First leTTeR of EACH Word".to_string();
let res = "First Letter of Each Word".to_string();
assert_eq!(Solution::capitalize_title(title), res);
let title = "i lOve leetcode".to_string();
let res = "i Love Leetcode".to_string();
assert_eq!(Solution::capitalize_title(title), res);
}
``````