#include<stdio.h>

#include<stdlib.h>

#define N 9

typedef struct node{

int data;

struct node * next;

}ElemSN;

ElemSN * Createlink(int a[]){ //逆向创建单向链表

int i;

ElemSN * h=NULL, * p;

for( i=N-1;i>=0;i--){

p=(ElemSN *)malloc(sizeof(ElemSN));

p->data =a[i];

p->next=h;

h=p;

}

return h;

}

void Printlink(ElemSN * h){

ElemSN * p;

for(p=h;p;p=p->next){

printf("%2d\n",p->data);

}

}

ElemSN * DelSamenode(ElemSN*h){

ElemSN * p, * q, * Pkey;//p,q指针联动 Pkey哨兵，p指针的值与PKey比较，相等就删除，不相等pq联动

Pkey=h;

while(Pkey){

q=Pkey;

p=Pkey->next;

while(p){

if(Pkey->data!=p->data){ //不等，pq联动

q=p;

p=p->next;

}

else{

q->next=p->next;

free(p); //先释放p，p再后移，否则剩余的链就挂在了p指针后面以释放后面的链就找不到头指针，属于游离状态

p=q->next;

}

}

Pkey=Pkey->next; //Pkey每次后移一位

}

return h;

}

int main(void){

int a[]={2,2,3,4,2,3,3,2,5};

ElemSN * head;

head=Createlink(a,9);

head=DelSamenode(head);

Printlink(head);

}