一元多项式求导

#include <stdio.h>
#include <string.h>

struct N{
    int c;
    int e;
}buf[1010],ans[1010];
int main()
{
  freopen("data.in","r",stdin);
  freopen("d1.out","w",stdout);
  int x,y,index=0,k=0,i;
  while(scanf("%d%d",&x,&y)!=EOF)
    {
      buf[index].c=x;
      buf[index].e=y;
      if(buf[index].e==0)
    break;
      index++;
    }
k=index;
if(k==0)
    printf("0 0");
else
  {
  for(i=0;i<index-1;i++)
    {    if(buf[i].e!=0)
      printf("%d %d ",buf[i].c*buf[i].e,buf[i].e-1);
    }

    printf("%d %d",buf[i].c*buf[i].e,buf[i].e-1);
  }

  return 0;
}