```
#include<bits/stdc++.h>
using namespace std;
int a[11451],b[11451],c[11451];
string jian(string a2,string b2);
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
string a,b;
cin>>a>>b;
cout<<jian(a,b);
return 0;
}
string jian(string a2,string b2)
{
if (a2.size()<b2.size())
{
cout<<'-';
swap(a2,b2);
}
else if (a2.size()==b2.size())
{
if (a2<b2)
{
cout<<'-';
swap(a2,b2);
}
}
memset(a,0,sizeof(a));
memset(b,0,sizeof(b));
memset(c,0,sizeof(c));
int len=max(a2.size(),b2.size());
string k="";
for (int i=a2.size()-1,j=1;i>=0;i--,j++)
{
a[j]=a2[i]-'0';
}
for (int i=b2.size()-1,j=1;i>=0;i--,j++)
{
b[j]=b2[i]-'0';
}
for (int i=1;i<=len;i++)
{
c[i]+=a[i]-b[i];
if (c[i]<0)
{
c[i]+=10;
c[i+1]--;
}
}
while (c[len]==0)
{
len--;
}
for (int i=max(1,len);i>=1;i--)
{
k+=c[i]+'0';
}
return k;
}
```
by xzy_AK_IOI @ 2024-04-14 16:16:15