。。。

#include <iostream>
#include <ctype.h>

 

using namespace std;

//#include "class_a.h"

int main(int argc, char *argv[])
{
      string line;
      int year;
     
      while( 1 )
      {

   
       cout << "请输入年(四位整数，范围1900~3000):";
   
       getline(cin, line);
   
       if(line.size() != 4)
          { cout << "输入不是四位，请重新输入!"<< endl;
            continue;
          }
         
          bool bCheck = true;
          for( int i = 0; i < line.size(); i++ )
          {
              if( !isdigit( line[i]) )
              {
                 
                  bCheck = false;
                  break;
              }
          }
         
          if( !bCheck )
          {
           cout << "输入不是整数类型年,请重新输入!" << endl;
           continue;   
          }
         
   
       year = atoi( line.c_str() );
   
       if( year <1900 || year >3000 )
          {
              cout << "输入错误，不在范围内，请重新输入!" << endl;
            continue;
           }
          
           break;
      
       }

 

  cout << year <<endl;
   
    system("PAUSE");
    return EXIT_SUCCESS;
}