creat函数根据用户输入的多行字符串建立一个,当某行输入字符串是”##”,则结束创建;所得头指针作为函数返回值。在______处填写适当内容,完成该程序。 struct exm{ char name[8]; struct exm *next; }; struct exm *creat() { struct exm *phead=0; struct exm* pnew,*pend; int i=0; pend=pnew=(struct exm*)malloc(sizeof(struct exm)); pnew->next=0; scanf("%s",pnew->name); while(strcmp(pnew->name, "##")!=0) { i++; if(i==1) { pend=pnew; phead=pnew; } else { pend->next=pnew; pend=pnew; } pnew=(struct exm*)malloc(sizeof(struct exm)); scanf("%s",pnew->name); pnew->next=NULL } free(_________); return phead; };