剑指 Offer II 058. 左旋转字符串 #

class Solution {
    public void swap(char[] charArray, int i, int j) {
        char temp = charArray[i];
        charArray[i] = charArray[j];
        charArray[j] = temp;
    }
    public String reverseLeftWords(String s, int n) {
        char[] charArray = s.toCharArray();
        for (int i = 0, j = charArray.length - 1; i < j; i++, j--) swap(charArray, i, j);
        for (int i = 0, j = charArray.length - n - 1; i < j; i++, j--) swap(charArray, i, j);
        for (int i = charArray.length - n, j = charArray.length - 1; i < j; i++, j--) swap(charArray, i, j);
        return String.valueOf(charArray);
    }
}