Leet_Code_567_字符串排列

public static boolean checkInclusion(String s1, String s2) {
        int[] charArray1 = new int[26];
        int[] charArray2 = new int[26];
        for (char c : s1.toCharArray()) {
            charArray1[c-'a'] ++;
        }
        int length = s1.length();
        for (int i=0;i<s2.length();i++) {
            charArray2[s2.charAt(i) - 'a'] ++;
            if (i >= length) {
                int left = i-length;
                charArray2[s2.charAt(left)- 'a'] --;
            }
            if (Arrays.equals(charArray1, charArray2))
                return true;
        }
        return false;
    }