大数的除法 不使用BigInteger Java实现

import java.util.Arrays;

public class Solution {
    public void div(String a, String b) {

        char[] chara = a.toCharArray();
        char[] charb = b.toCharArray();
        int[] numa = new int[a.length()];
        int[] numb = new int[b.length()];
        for (int i = 0; i < charb.length; i++) {
           numb[i] = charb[i]-'0';
     //      System.out.print(""+numb[i]);
        }
        System.out.println("");
        for (int i = 0; i < chara.length; i++) {
            numa[i] = chara[i]-'0';
         System.out.print(""+numa[i]);
        }
        System.out.println("");
        int[] div = new int [1000];
        int count = 0;
        while(compare(numa,numb)>0){
            numa= div(numa,numb);
            addSelf(div,count);

        }
        StringBuffer sb =  new StringBuffer();
        sb.append(""+div+"  ");
        for (int i = 0; i < numa.length; i++) {
            sb.append(""+numa[i]);
        }
        System.out.println(""+sb);
    }

    private void addSelf(int[] div, int count) {
        if (div[div.length-1]!=9) {
            div[div.length-1]++;
        }else{
            int i = div.length-1;
            while (div[i]==9){
                div[i] = 0;
                i--;
            }  ;
            if (div[i]==0) {
                count++;
            }else{
                div[i] ++;
            }

            }

    }

    private int[] div(int[] numa, int[] numb) {
        for (int i = 0; i < numb.length; i++) {
            int tmpa = numa[numa.length-i-1];
            int tmpb = numb[numb.length-i-1];
            int sub =  tmpa-tmpb;
            int count = numa.length-1;
            if (sub>=0) {
                numa[numa.length-i-1] = sub;
            }else{
                numa[numa.length-i-1] = sub+10;
                count =numa.length- i-1-1;
                while(numa[count]==0){
                    numa[count] =9;
                    count--;

                }
                numa[count]--;
                if (numa[0]==0) {
                    numa = Arrays.copyOfRange(numa,1, numa.length);

                }
            }

        }

        for (int i = 0; i < numa.length; i++) {
        //    System.out.print(""+numa[i]);
        }
        //System.out.println("");
        return numa;
    }

    int compare(int[] numa, int[] numb) {
        if (numa.length<numb.length) {
            return -1;
        }else if (numa.length>numb.length) {
            return 1;
        }else{
            for (int i = 0; i < numb.length; i++) {
                if (numa[i]>numb[i]) {
                    return 1;
                }
                if (numa[i]<numb[i]) {
                    return -1;
                }
            }
            return 0;
        }

    }
public static void main(String[] args) {
    Solution solution = new Solution();
    String a = "1234578901234567890123456789";
    String b = "1";
    solution.div(a, b);
}
}