链串的基本运算

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define CHUNKSIZE 10
#define stuff '#'
typedef struct Chunk
{
char ch[CHUNKSIZE];
struct Chunk *next;
}Chunk;//串的结点类型定义
typedef struct
{
Chunk *head;
Chunk *tail;
int length;
}LinkString;

void InitString(LinkString *S);//初始化字符串
int StrAssign(LinkString *S,char *cstr);//生成串
int StrEmpty(LinkString S);//判断出串是否为空
int StrLength(LinkString S);//求串长度
int StrCopy(LinkString *T,LinkString S);//串的复制操作
int ToChars(LinkString S,char **cstr);//串的转换操作
int StrCompare(LinkString S,LinkString T);//串的比较操作
int StrConcat(LinkString *T,LinkString S);//串的连接操作
int StrInsert(LinkString *S,int pos,LinkString T);//串的插入操作
int StrDelete(LinkString *S,int pos,int len);//串的删除操作
int SubString(LinkString *Sub,LinkString S,int pos,int len);//取子串操作
void ClearString(LinkString *S);//清空串操作

#include "LinkString.h"

void InitString(LinkString *S)//初始化字符串
{
S->length = 0;
S->head = NULL;
S->tail = NULL;
}
int StrAssign(LinkString *S,char *cstr)//生成串
{
Chunk *p,*q;
int i,j,k,len;
len = strlen(cstr);
if(!len)
{
return 0;
}
S->length = len;
j = len/CHUNKSIZE;
if(len % CHUNKSIZE)
{
j++;
}
for(i = 0;i < j;i++)
{
p = (Chunk*)malloc(sizeof(Chunk));
if(!p)
{
return 0;
}
for(k = 0;k < CHUNKSIZE && *cstr;k++)
{
*(p->ch + k) = *cstr++;
}
if(0 == i)
{
S->head = q;
q = p;
}
else
{
q->next = p;
q = p;
}
if(!*cstr)
{
S->tail = q;
q->next = NULL;
for(;k < CHUNKSIZE;k++)
{
*(q->ch + k) = stuff;
}
}
}
return 1;
}
int StrEmpty(LinkString S)//判断出串是否为空
{
if(S.length == 0)
{
return 1;
}
else
{
return 0;
}
}
int StrLength(LinkString S)//求串长度
{
return S.length;
}
int StrCopy(LinkString *T,LinkString S)//串的复制操作
{
char *str;
int flag;
if(!ToChars(S,&str))
{
return 0;
}
flag = StrAssign(T,str);
free(str);
return flag;
}
int ToChars(LinkString S,char **cstr)//串的转换操作
{
Chunk *p = S.head ;
int i;
char *q;
*cstr = (char*)malloc((S.length + 1)*sizeof(char));
if(!cstr||!S.length)
{
return 0;
}
q = *cstr;
while(p)
{
for(i = 0;i < CHUNKSIZE;i++)
{
if(p->ch[i] != stuff)
{
*q++ = (p->ch[i]);
}
}
p = p->next ;
}
(*cstr)[S.length] = 0;
return 1;
}
int StrCompare(LinkString S,LinkString T)//串的比较操作
{
char *p,*q;
int flag;
if(!ToChars(S,&p))
{
return 0;
}
if(!ToChars(T,&q))
{
return 0;
}
for(;*p != '\0'&&*q != '\0';)
{
if(*p == *q)
{
p++;
q++;
}
else
{
flag = *p - *q;
}
}
free(p);
free(q);
if(*p == '\0'||*q == '\0')
{
return S.length - T.length ;
}
else
{
return flag;
}
}
int StrConcat(LinkString *T,LinkString S)//串的连接操作
{
int flag1,flag2;
LinkString S1,S2;
InitString(&S1);
InitString(&S2);
flag1 = StrCopy(&S1,*T);
flag2 = StrCopy(&S2,S);
if(flag1 == 0 || flag2 == 0)
{
return 0;
}
T->head = S1.head ;
S1.tail->next = S2.head ;
T->tail = S2.tail ;
T->length = S1.length + S2.length ;
return 1;
}
int StrInsert(LinkString *S,int pos,LinkString T)//串的插入操作
{
char *t1,*s1;
int i,j;
int flag;
if(pos < 1 || pos > S->length-1)
{
return 0;
}
if(!ToChars(*S,&s1))
{
return 0;
}
if(!ToChars(T,&t1))
{
return 0;
}
j = strlen(s1);
s1 = (char*)realloc(s1,(j+strlen(t1)+1)*sizeof(char));
for(i = j;i >= pos-1;i--)
{
s1[i+strlen(t1)] = s1[i];
}
for(i = 0;i <(int)strlen(t1);i++)
{
s1[pos+i-1] = t1[i];
}
InitString(S);
flag = StrAssign(S,s1);
free(s1);
free(t1);
return flag;
}
int StrDelete(LinkString *S,int pos,int len)//串的删除操作
{
char *str;
int i;
int flag;
if(pos < 1 || len < 0 || pos > S->length-len+1)
{
return 0;
}
if(!ToChars(*S,&str))
{
return 0;
}
for(i = pos+len-1;i <= (int)strlen(str);i++)
{
str[i-len] = str[i];
}
InitString(S);
flag = StrAssign(S,str);
free(str);
return flag;
}
int SubString(LinkString *Sub,LinkString S,int pos,int len)
{
char *t,*str;
int flag;
if(pos < 1||pos > S.length||len < 0||len > S.length - pos + 1)
{
return 0;
}
if(!ToChars(S,&str))
{
return 0;
}
t = pos+str-1;
t[len] = '\0';
flag = StrAssign(Sub,t);
free(str);
return flag;
}//取子串操作
void ClearString(LinkString *S)//清空串操作
{
Chunk *p,*q;
p = S->head ;
while(p)
{
q = p->next ;
free(p);
p = q;
}
S->head = NULL;
S->tail = NULL;
S->length = 0;
}