求字符的C++程序

#include <iostream>
 
using namespace std;
 
int main()
 
{
 
      char c;
 
      int letters=0,space=0,digit=0,others=0;
 
      cout<<"please input some characters"<<endl;
 
      while((c=getchar())!='\n')
 
      {
 
            if(c>='a'&&c<='z'||c>='A'&&c<='Z')
 
                  letters++;
 
            else if(c==' ')
 
                  space++;
 
            else if(c>='0'&&c<='9')
 
                  digit++;
 
            else
 
                  others++;
 
      }
 
      printf("all in all:char=%d space=%d digit=%d others=%d\n",letters,space,digit,others);
 
      system("pause");
 
      return 0;
 
}