763. Partition Labels

A string `S` of lowercase English letters is given. We want to partition this string into as many parts as possible so that each letter appears in at most one part, and return a list of integers representing the size of these parts.

Example 1:

```Input: S = "ababcbacadefegdehijhklij"
Output: [9,7,8]
Explanation:
The partition is "ababcbaca", "defegde", "hijhklij".
This is a partition so that each letter appears in at most one part.
A partition like "ababcbacadefegde", "hijhklij" is incorrect, because it splits S into less parts.
```

Note:

• `S` will have length in range `[1, 500]`.
• `S` will consist of lowercase English letters (`'a'` to `'z'`) only.

763. Partition Labels
``````struct Solution;
use std::collections::HashMap;

impl Solution {
fn partition_labels(s: String) -> Vec<i32> {
let mut res = vec![];
let mut last: HashMap<char, usize> = HashMap::new();
for (i, c) in s.char_indices() {
last.insert(c, i);
}
let mut start = 0;
let mut end = 0;
for (i, c) in s.char_indices() {
let j = last[&c];
if j > end {
end = j;
}
if i == end {
res.push((end - start + 1) as i32);
start = last[&c] + 1;
end = last[&c] + 1;
}
}
res
}
}

#[test]
fn test() {