1750. Minimum Length of String After Deleting Similar Ends - Medium

前往題目

想法

• 雙指針

思路

1. 雙指針，指向兩端
2. 當l指針小於r，也都指向同樣的字符，持續循環
3. 每個循環都盡可能的移動左指針和右指針
4. 輸出剩下幾個字符

Code

class Solution {
    public int minimumLength(String s) {
        int l = 0, r = s.length() - 1;

        // Until intersect or characters don't match
        while (l < r && s.charAt(l) == s.charAt(r)) {
            char ch = s.charAt(l);

            // Shift left pointer
            while (l <= r && s.charAt(l) == ch) {
                ++l;
            }

            // Shift right pointer
            while (l <= r && s.charAt(r) == ch) {
                --r;
            }
        }
        return r - l + 1;
    }
}