1446. Consecutive Characters

/**
1446. Consecutive Characters
https://leetcode.com/problems/consecutive-characters/
The power of the string is the maximum length of a non-empty substring that contains only one unique character.
Given a string s, return the power of s.

Example 1:
Input: s = "leetcode"
Output: 2
Explanation: The substring "ee" is of length 2 with the character 'e' only.

Example 2:
Input: s = "abbcccddddeeeeedcba"
Output: 5
Explanation: The substring "eeeee" is of length 5 with the character 'e' only.

Example 3:
Input: s = "triplepillooooow"
Output: 5

Example 4:
Input: s = "hooraaaaaaaaaaay"
Output: 11

Example 5:
Input: s = "tourist"
Output: 1

Constraints:
1. 1 <= s.length <= 500
2. s consists of only lowercase English letters.
*/
pub struct Solution {}

impl Solution {
    /*
    Solution: keep tracking each char and the maximum consecutive length, Time:O(n), Space:O(1)
    */
    pub fn max_power(s: String) -> i32 {
        let (mut max, mut currentMax, mut lastChar) = (0, 0, '_');
        for c in s.chars() {
            if (lastChar == c) {
                max += 1;
                currentMax = std::cmp::max(currentMax,max);
            } else {
                max = 1;
            }
            lastChar = c;
        }
        std::cmp::max(currentMax,1)
    }
}