行程编码（atoi函数）

 #include<iostream>
 #include<string>
 #include<vector>
 using namespace std;
 void jiema(string s)
 {
     cout << "解码之后为：" << endl;
     for(int i = ; i < s.size(); i++)
     {
         if(s[i + ] == '*')
         {
             int j = i + ;
             int len = ;
             while(s[j + ] >=  && s[j + ] <= )
             {
                 len++;
                 j = j + ;
             }
             string temp = s.substr(i + , len);
             int num = atoi(temp.c_str());
             for(int k = ; k < num; k++)
             {
                 cout << s[i];
             }
             i = j;
         }
         else
         {
             cout << s[i];

         }
     }
 }
 void bianma(string s)
 {
     vector<char>A;
     int p = ;
     int j = ;
     for(; j < s.size();)
     {
         while(s[j] == s[j + ] && j < s.size())
         {
             p++;
             j = j + ;
         }
         if(p >= )
         {
             A.push_back(s[j]);
             A.push_back('*');
             A.push_back(p);
             p = ;
             j = j + ;
         }
         else if(p < )
         {
             for(int k = ; k < p; k++)
             {
                 A.push_back(s[j]);
             }
             p = ;
             j = j + ;
         }
     }
     cout << "编码之后为：" << endl;
     for(int b = ; b < A.size(); b++)
     {
         if(A[b] >=  && A[b] <= )
             cout << int(A[b]);
         else
             cout << A[b];
     }
     cout << endl;
     cout << "压缩比为：" << endl;
     double y = double(A.size()) / s.size();
     cout << y << endl;
 }
 void main()
 {
     cout << "请输入代码：①代码中含有数字表示需要解码解压缩②代码中不含数字表示需要编码压缩" << endl;
     string s;
     for(; cin >> s;)
     {
         int i = ;
         for(; i < s.size(); i++)
         {
             if(s[i] >=  && s[i] <= ) //解码
             {
                 jiema(s);
                 break;
             }
         }
         if(i == s.size())
         {
             bianma(s);
         }
     }
 }