917. Reverse Only Letters.md

917. Reverse Only Letters

Reverse Only Letters - LeetCode

code1

class Solution {
    public String reverseOnlyLetters(String s) {
        char[] arr = s.toCharArray();
        int i = 0 , j = s.length()-1;

        while (i < j)
        {
            char c1 = arr[i];
            char c2 = arr[j];
            if (Character.isLetter(c1) && Character.isLetter(c2)) {
                arr[i++] = c2;
                arr[j--] = c1;
            }
            if(!Character.isLetter(c2)){
                j--;
            }
            if (!Character.isLetter(c1)){
                i++;
            }
        }

        return new String(arr);

    }
}

code2

class Solution {
    public String reverseOnlyLetters(String s) {
        StringBuilder str = new StringBuilder();
        for (int i = s.length()-1 ; i >= 0 ; i--) {
            char c1 = s.charAt(i);
            if (Character.isLetter(c1)) str.append(c1);
        }

        for (int i = 0; i < s.length(); i++) {
            char c1 = s.charAt(i);
            if (!Character.isLetter(c1)) str.insert( i , c1);
        }
        return str.toString();
    }
}