为啥while(a[i]=b[k])不行

为什么while(a[i]=b[k])不行
#include <iostream>
#include <string>
using namespace std;

int main()
{
     char a[30];
     cin.get(a,30);
     char b[5]="done";
      int i,k,space,d=0;
      while (d!=3 or i==50)
      {
            while(a[i]==b[k])
            {
                   cout<<'5';
                   if (d==3)
                   {
                        cout<<"done. you've entered "<<space<<" words"; break;
                   }
                   i=i+1;
                   k=k+1;
                   d=k;
               }    
                   if (a[i]==' ')
                   space=space+1;
                   if(k!=3)
                   k=0;
                   else
                   break;
                   i=i+1;
      }
      return 0;
} 
  

[解决办法]
代码应该没有什么大问题,先把i,k初始化一下，再在最下面的return 0前,加上两个getchar();getchar();就可以看到运行结果了。
[解决办法]


......
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我的是c++builder6,你用的什么编译器,不知道是否是兼容性的问题.不知道上图是不是你要的效果?代码如下:

//---------------------------------------
#include <iostream>
#include <string>
#include <vcl.h>
#pragma hdrstop
using namespace std;
//---------------------------------------

#pragma argsused
int main(int argc, char* argv[])
{
      char a[30];
      cin.get(a,30); 
 
      char b[5]="done";
      int i=0,k=0,space=0,d=0;
      while (d!=3 
[解决办法]
 i==50)
      {
            while(a[i]==b[k])
            {
                   cout<<'5';
                   if (d==3)
                   {
                        cout<<"done. you've entered "<<space<<" words"; break;
                   }
                   i=i+1;
                   k=k+1;
                   d=k;
            }
                   if (a[i]==' ')
                   space=space+1;
                   if(k!=3)
                   k=0;
                   else
                   break;
                   i=i+1;
      }
      getchar();
      getchar();
      return 0;
}
//---------------------------------------