双链表基本操作

/******************************************************************************

  Copyright (C), 2001-2011, Huawei Tech. Co., Ltd.

 ******************************************************************************

  File Name     : 

  Version       : 

  Author        : 

  Created       : 2012/03/12

  Last Modified :

  Description   : 

  Function List :

              

  History       :

  1.Date        : 2012/03/12

    Author      : 

    Modification: Created file

******************************************************************************/

#include <stdlib.h>

#include <string.h>

#define null 0

#define MAXSIZE 50

struct strlnode

{
int data;
struct strlnode *plast;
struct strlnode *pnext;

};

void create(struct strlnode **p, int x)  /*创建双链表(表头节点)*/

{
struct strlnode *q;

q = (struct strlnode *)malloc(sizeof(struct strlnode));
q->data = x;
q->plast = null;
q->pnext = null;

*p = q;

return;

}

void insertnode(struct strlnode **p, int i, int x) /* 在链表第i个位置插入数据等于x的节点 */

{
if(*p==null)
return;
struct strlnode *temp=*p,*save=*p,*t;
int count=0;
while(temp->pnext!=null)
{
count++;
temp=temp->pnext;
}
if(i<0||i>count+1)
return;

/* 代码在这里实现 */
struct strlnode *q=(strlnode *)malloc(sizeof(strlnode));

q->data=x;

    
if(i==0)
{
q->pnext=save;
q->plast=null;
save->plast=q;
*p=q;
return;
}
else
if(i==count+1)
{
q->pnext=null;
q->plast=temp;
temp->pnext=q;
return;
}
else
{
count=0;
while(count!=i)
{
 count++;
 t=save;
 save=save->pnext;
 
}
q->pnext=t->pnext;
save->plast=q;
q->plast=t;
t->pnext=q;
return;

}

}

void deletenode(struct strlnode **p, int i) /* 删除链表中第i个节点 */

{
/* 代码在这里实现 */
if(*p==null)
return;
struct strlnode *temp=*p,*save=*p,*t;
int count=0;
while(temp->pnext!=null)
{
count++;
temp=temp->pnext;
}
if(i<0||i>count+1)
return;
// delete the node 
if(i==0)
{  if(count==0)
   *p=null;
save=save->pnext;
save->plast=null;

        *p=save;
return;
}
else
if(i==count+1)
{
t=temp->plast;
t->pnext=null;
free(temp);

return;
}
else
{
   count=0;
while(count!=i)
{
 count++;
 t=save;
 save=save->pnext;
 
}
save->pnext->plast=save->plast;
t->pnext=save->pnext;
free(save);
return;

}

}

int getnodenum(struct strlnode **p)  /*获取链表中节点个数*/

{
int nodenum = 0;
/* 代码在这里实现 */

    if(*p==null)
return nodenum;
strlnode *temp=*p;
while(temp->pnext!=null)
{
nodenum++;
temp=temp->pnext;
}

return nodenum+1;

}

void readtolnode(struct strlnode **p, int *a, int size)  /* 将数组写入链表中，链表中的数据的先后顺序和数组中的顺序要保持一致 */

{
int j = 0;
int data = 0;
struct strlnode *s = *p;

s->data = *(a + (size-1));

for(j = 2; j < (size+1); j++)
{
data = *(a + (size-j));
insertnode(p, 0, data);
}

return;

}

void writetosqlist(int *a, struct strlnode *p)  /* 将链表写入数组中，数组中的数据的先后顺序和链表中的顺序要保持一致 */

{
int j = 0;
struct strlnode *s = p;

while(s != null)
{
*(a + j) = s->data;
s = s->pnext;
j++;
}

return;

}

void bignumberplus(struct strlnode **plus, struct strlnode **p, struct strlnode **q) /* 使用链表实现大整数相加 */

{
/* 代码在这里实现 */

 
int lenp = getnodenum(p);
int lenq = getnodenum(q);
int a[10000] = {0};
int b[10000] = {0};
int len = lenp > lenq ? lenp : lenq;
struct strlnode *pl = *p;
struct strlnode *ql = *q;
for(int i = lenp - 1; i>= 0; i--)
{
a[i] = pl->data;
pl = pl ->pnext;
}
for(int i = lenq - 1; i>= 0; i--)
{
b[i] = ql->data;
ql = ql ->pnext;
}
for(int i = 0; i < len; i++)
{
a[i] = a[i] + b[i];
if(a[i]>=10)
{
a[i+1] += a[i] / 10;
a[i] %= 10;
}
}
if(a[len] != 0)//最后进位后会多出来的
len++;
(*plus)->data = a[len -1];
int j = 1;
for(int  i = len - 2; i>= 0 ;i--)
{
int data = a[i];
insertnode(plus, j, data);
j++;
}
return;

}