寻找字符串中联系数字（全部都是1位数）之和为k的子串

package com.test;

public class SubString1 {

    public static void main(String[] args) {
        String str = "20210521";
        int k = 6;
        String res = new SubString1().splitStr(str, k);
        System.out.println(res);
    }

    public String splitStr(String str, int k) {
        //标识符，找到，直接结束
        boolean flag = false;
        //保存结果
        String result = "";
        //转换成数组
        int[] array = convertStrArray(str);
        for(int i = 0; i < array.length - 1; i++) {
            //里面循环结束，将total置为0
            int total = 0;
            //里面循环结束，将result结果清空，用于保存下一次循环的结果
            result = "";
            //累加
            total += array[i];
            //字符串结果集拼接
            result += array[i];
            for(int j = i + 1; j < array.length; j++) {
                total += array[j];
                result += array[j];
                //是否找到
                if(total == k) {
                    //找到，将flag置为true,并结束循环
                    flag = true;
                    break;
                }
            }
            //找到，结束外层循环
            if(flag){
                break;
            }
        }
        return result;
    }

    
    public int[] convertStrArray(String str){
        //先把字符串转成数组
        String[] split = str.split("");
        int index = 0;
        //将字符串中的元素全部放到int类型的数组中，进行后期的运算操作
        int[] array = new int[split.length];
        for(int i = 0; i < split.length; i++) {
            array[index] = Integer.parseInt(split[i]);
            index++;
        }
        return array;
    }
}

s = input("请输入数字字符串");
i = 0; j = 0; k = 6; sum = 0;
while j < len(s):
    ch1 = s[j];
    sum = sum + int(ch1)
    while sum > k:
        ch2 = s[i]
        sum = sum - int(ch2)
        i = i + 1
    if sum == k:
        print("字串为:", s[i:j + 1])
        break;
    j += 1
else:
    print("没有满足要求的子串")