输入样例：
1234567 368782971
输出样例：
3695Q8118
思路很容易就能想到。注意，如果两个数字长度不相等，需要在短的那一个数字前面补零。
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <string>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>using namespace std;void encryption(vector<int> s1,vector<int> s2);int main()
{vector<int> s1,s2;char c;c=getchar();while(c!=' '&&c!='\n'){s1.push_back(c-'0');c=getchar();}c=getchar();while(c!=' '&&c!='\n'){s2.push_back(c-'0');c=getchar();}//补全两个字符串的长度if(s1.size()>s2.size()){while(s1.size() != s2.size())s2.insert(s2.begin() ,0);}if(s1.size()<s2.size()){while(s1.size() != s2.size())s1.insert(s1.begin() ,0);}encryption(s1,s2);return 0;
}void encryption(vector<int> s1,vector<int> s2)
{reverse(s1.begin(),s1.end());reverse(s2.begin(),s2.end());for(int i=0; i<s2.size(); i++){if((i+1)%2==0){s2[i]-=s1[i];if(s2[i]<0)s2[i]+=10;}elses2[i]=(s2[i]+s1[i])%13;}reverse(s2.begin(),s2.end());for(vector<int>::iterator itor=s2.begin(); itor!=s2.end() ; itor++){switch(*itor){case 10:cout<<'J';break;case 11:cout<<'Q';break;case 12:cout<<'K';break;default:cout<<*itor;}}
}