>#include<iostream>
```cpp
#include<cstdio>
#include<cmath>
using namespace std;
string str;
int st,a[100],l,p10[5]={1,10,100,1000,10000};
int main(){
int n=0,x,i,s,t,ps;
cin>>str;
cin>>st;
l=str.length();
for (i=0;i<l;i++){
x=str[i]-65+st;
if (x<10){
n++;
a[n]=x;
}
else{
s=0;
t=x;
while (t>0){
s++;
t=t/10;
}
while (s>0){
ps=p10[s-1];
n++;
a[n]=x/ps;
x=x%ps;
s--;
}
}
}
```
/\*
for (i=1;i<=n;i++){
cout<<a[i]<<' ';
}
\*/
```cpp
//cout<<n<<endl;
while (n>2){
n--;
if (n==2 && a[1]==1 && a[2]==0 && a[3]==0){
cout<<"100";
return 0;
}
for (i=1;i<=n;i++){
//cout<<a[i];
a[i]=(a[i]+a[i+1])%10;
}
//cout<<a[n+1]<<endl;
}
cout<<a[1]<<a[2];
return 0;
}
```
by WarriorWdk @ 2017-08-03 21:14:15
@[王德坤lele](/space/show?uid=20426) 答案输出时可能有前导0，应该在处理过程中去掉，并且在结果输出时做判断，也可以用string+stringstream做，很好写
by RiverHamster @ 2017-08-31 16:52:25
@ RiverHamster 谢谢，A了
by WarriorWdk @ 2017-09-03 13:19:22
@[王德坤lele](/space/show?uid=20426) 请问您是怎么改的？我改了以后RE
by wuyutong111 @ 2018-11-18 17:14:22
不用了，已A
by wuyutong111 @ 2018-11-18 17:33:52