对称子字符串

对称子字符串

Description

Given a string ‘str’ of digits, find length of the longest substring of ‘str’, such that the length of the substring is 2k digits and sum of left k digits is equal to the sum of right k digits.

给定一个数字字符串' str '，找出' str '的最长子串的长度，使该子串的长度为2k，且左k位数字的和等于右k位数字的和。

Input

输入第一行是测试用例的个数，后面每一行表示一个数字组成的字符串，例如："123123"

Output

输出找到的满足要求的最长子串的长度。例如，给定的例子长度应该是 6。每行对应一个用例的结果。

Sample Input

1
1538023

Sample Output

4

Solution

public class SymmetricalSubstr {

    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int caseNum = in.nextInt();
        for(int i = 0; i < caseNum; i++){
            in.nextLine();
            String str = in.next();
            System.out.println(getLongestLen(str));
        }
    }

    public static int getLongestLen(String str){
        int max = 0;
        int strLen = str.length();
        for(int i = 0; i < strLen - 1; i++){
            int left = i;
            int right = i + 1;
            int leftSum = 0;
            int rightSum = 0;
            while(left >= 0 && right < strLen){
                leftSum += str.charAt(left) - '0';
                rightSum += str.charAt(right) - '0';
                if(leftSum == rightSum){
                    max = Math.max(max, right - left + 1);
                }
                left--;
                right++;
            }
        }
        return max;
    }
}