Java 大数A+B

public class Solution {
    public int length = 0;

    public Object[] numToArrays(int num) {
        List<Integer> list = new ArrayList<Integer>();
        while (num / 10 != 0) {
            list.add((num) % 10);
            num /= 10;
        }
        list.add(num % 10);
        return list.toArray();
    }
    
    public Object[] stringToArrays(String s1){
        Object[] strs = new Integer[s1.toCharArray().length];
        char[] chs = s1.toCharArray();
        for(int i=strs.length-1;i>=0;i--){
            strs[strs.length-1-i] = Integer.parseInt(String.valueOf(chs[i]));
        }
        return strs;
    }

    public int[] bigSum(Object a, Object b) {
        length = 0;
        boolean isUp = false;
        int[] result = new int[10000];
        Object[] as = null;
        Object[] bs = null;
        if(a instanceof String){
            as = stringToArrays((String)a);
            bs = stringToArrays((String)b);
        }else if(a instanceof Integer){
        as = numToArrays((int)a);
        bs = numToArrays((int)b);
        }
        

        int i = 0;
        int s = Math.min(as.length, bs.length);
        Object[] larrays = as.length >= bs.length ? as : bs;
        int l = larrays.length;
        for (; i < s; i++) {
            int c = (int) as[i] + (int) bs[i] + result[i];
            if (c >= 10) {
                // 进位,需增高一位
                result[i + 1] += 1;
                // 本位取余
                result[i] = c % 10;
                if (i + 1 >= s) {
                    isUp = true;
                }
            } else {
                result[i] = c;

            }
            length++;
        }
        int flag=0;
        if (isUp){
            length++;
            flag=1;    
        }
        isUp = false;
        // 处理不等长
        if (s != l) {
            for (int k = length-flag; k < l; k++) {
                int temp = result[k] + (int) larrays[k];
                if (temp >= 10) {
                    result[k] = temp % 10;
                    result[k + 1] = 1;
                    if (k + 1 >= l) {
                        isUp = true;
                    }
                } else {
                    result[k] = temp;
                }
                length++;
            }
            if(flag==1){
                length--;
            }
        }
        if (isUp)
            length++;
        return result;
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Solution s = new Solution();
        int[] list = s.bigSum("164455462456282903781237128937128937812937812973891272389456456222","123245445243512");
        for (int i = s.length - 1; i >= 0; i--) {
            System.out.print(list[i]);
        }
    }

输出:164455462456282903781237128937128937812937812973891395634901699734