如果去掉s3=s1;就会不能AC
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main(){
string s1,s2,s3; cin>>s1;
int cnt=0,jinwei=0;
for(cnt;cnt<10;cnt++){
s2=s1; //s2存储原来的字符串
s3=s1;
reverse(s1.begin() ,s1.end() ) ; //s1逆转
if(s1==s2){
cout<<s1<<" is a palindromic number.";
break;
}
for(int i=0;i<s1.length() ;i++){
s3[i]=(s1[i]-'0'+s2[i]-'0'+jinwei)%10+'0';
jinwei=(s1[i]-'0'+s2[i]-'0'+jinwei)/10;
}
reverse(s3.begin() ,s3.end() );
if(jinwei) s3='1'+s3;
cout<<s2<<" + "<<s1<<" = "<<s3<<endl;
s1=s3;
jinwei=0;
}
if(cnt==10) cout<<"Not found in 10 iterations.";
return 0;
}