In addition to high-precision high-precision

#include <iostream>
#include <string>
#include <cstring>
using namespace std;
string a1,b1;
int a[100001],b[100001],c[100001],t[100001];
int compare(int aa[],int bb[]) { //判断数组大小
    if (aa[0]>bb[0]) return 1;
    if (aa[0]<bb[0]) return -1;
    for (int i=aa[0]; i>0; i--) {
        if (aa[i]>bb[i]) return 1;
        if (aa[i]<bb[i]) return -1;
    }
    return 0;
}
void numcpy(int aa[],int bb[],int l) { //数组复制
    for (int i=1; i<=aa[0]; i++) bb[i+l-1]=aa[i];
    bb[0]=aa[0]+l-1;
}
int main() {
    cin>>a1>>b1;
    a[0]=a1.size();
    b[0]=b1.size();
    c[0]=a[0]-b[0]+1;
    for (int i=1; i<=a[0]; i++) a[i]=a1[a[0]-i]-48;
    for (int i=1; i<=b[0]; i++) b[i]=b1[b[0]-i]-48;
    for (int i=c[0]; i>0; i--) {
        memset(t,0,sizeof(t));
        numcpy(b,t,i);
        while (compare(a,t)>=0) {
            c[i]++;
            if (!compare(a,t)) {
                a[0]=0;
                continue;
            }
            for (int i=1; i<=a[0]; i++) {
                if (a[i]<t[i]) a[i+1]--,a[i]+=10;
                a[i]-=t[i];
            }
            while (a[0]>0&&!a[a[0]]) a[0]--;
        }
    }
    while (c[0]>0&&!c[c[0]]) c[0]--;
    if (!c[0]) cout<<0<<endl;
    else for (int i=c[0]; i>0; i--) cout<<c[i];
    return 0;
}