#include?“stdio.h“
struct?linkNode{
char?value;
struct?linkNode*?next;
};
struct?linkNode*?createlink（）;
int?addstr（struct?linkNode*?headNode?char?c）;
void?printstr（struct?linkNode*?headNode）;
main（）{
char?input;
struct?linkNode*?headNode;
headNode=createlink（）;
do{
input=getch（）;
if（（input>=‘0‘&&input<=‘9‘）||（input>=‘A‘&&input<=‘Z‘）||（input>=‘a(chǎn)‘&&input<=‘z‘）||input==‘?‘）{
printf（“%c“input）;
addstr（headNodeinput）;
}
if（input==‘\b‘）{
printf（“\b?\b“）;
}
if（input==‘\r‘）{
printf（“\r\n“）;
addstr（headNodeinput）;
}
}while（input!=27）??;
deletestr（headNode“aaa“）;
/*?replacestr（headNode“aaa““cccc“）;*/
printf（“\n“）;
printstr（headNode）;
printf（“\nspace?in?the?passage:%d“?countspace（headNode））;
printf（“\nchar?in?the?passage:%d“?countchar（headNode））;
printf（“\nword?in?the?passage:%d“?countword（headNode））;
printf（“\nnumber?in?the?passage:%d“?countnum（headNode））;
getch（）;

}
struct?linkNode*?createlink（）{
struct?linkNode*?h;
h=（struct?linkNode*）malloc（sizeof（struct?linkNode））;
h->next=NULL????;
h->value=NULL;
return?h;
}

int?addstr（struct?linkNode*?headNodechar?c）{
struct?linkNode*?unit;
struct?linkNode*??p;
unit=（struct?linkNode*）malloc（sizeof（struct?linkNode））;
unit->next=NULL;
unit->value=c;
p=headNode;
while（p->next!=NULL）p=p->next;?/*move?to?end;*/
p->next=unit;
}

void?printstr（struct?linkNode*?headNode）{
struct?linkNode*?p;
char?input;
p=headNode;
while（p->next!=NULL）{
p=p->next;
input=p->value;
if（（input>=‘0‘&&input<=‘9‘）||（input>=‘A‘&&input<=‘Z‘）||（input>=‘a(chǎn)‘&&input<=‘z‘）||input==‘?‘）{
printf（“%c“input）;???}
if（input==‘\r‘）{
printf（“\r\n“）;
}
}
}

int?countspace（struct?linkNode*?headNode）{
struct?linkNode*?p;
char?input;
int????count=0;
p=headNode;
while（p->next!=NULL）{
p=p->next;
input=p->value;
if（input==‘?‘）{
count++;
}
}
return?count;
}

int?countchar（struct?linkNode*?headNode）{
struct?linkNode*?p;
char?input;
int????count=0;
p=headNode;
while（p->next!=NULL）{
p=p->