https://leetcode.com/problems/swap-adjacent-in-lr-string/

swap-adjacent-in-lr-string.java

class Solution {
    public boolean canTransform(String start, String end) {
        int pt1 = 0, pt2 = 0;
        
        int len1 = start.length();
        int len2 = end.length();
        
        while(pt1 < len1 || pt2 < len2) {
            // find not X
            while(pt1 < len1 && start.charAt(pt1) == 'X') {
                pt1++;
            }
            // find not X
            while(pt2 < len2 && end.charAt(pt2) == 'X') {
                pt2++;
            }
            if (pt1 == len1 && pt2 == len2) {
                return true;
            }
            if (pt1 == len1 || pt2 == len2) {
                return false;
            }
            if (start.charAt(pt1) != end.charAt(pt2)) {
                return false;
            }
            if (start.charAt(pt1) == 'L' && pt1 < pt2) {
                return false;
            }
            if (start.charAt(pt1) == 'R' && pt1 > pt2) {
                return false;
            }
            pt1++;
            pt2++;
        }
        
        return true;
    }
}