题解 | #最长无重复子数组#

public class Main {//优化的中心点扩散法
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        while(sc.hasNextLine()) {
            String str=sc.nextLine();
            int len=str.length(),max=Integer.MIN_VALUE;
            int i=0;
            while(i<len) {
                int left=i-1;
                int right=i;
                while(++right<len&&str.charAt(right)==str.charAt(i)); //如 abbbbba  i=1指向b， right就直接循环到第二个a的下标
                i=right;
                while(left>=0&&right<len&&str.charAt(left)==str.charAt(right)) {
                    left--;
                    right++;
                }
                max=Math.max(max, right-left-1);
            }
            System.out.println(max);
        }
        sc.close();
    }
}