串的定长顺序存储(部分代码)

连接两个串:

串的第一个空间存储串长

#define MIXSIZE 100
typedef  int  Status;
typedef  char  SString[MIXSIZE+1];

Status Concat(SString *s3,SString s1,SString s2)
{

    if(s1[0]+s2[0]<=MIXSIZE)
    {
        printf("fgsd\n");
        for(int i=1;i<=s1[0];i++)
        {
            *s3[i]=s1[i];
        }
        for(int i=s1[0]+1;i<s1[0]+s2[0];i++)
        {
            *s3[i]=s2[0];
        }
        *s3[0]=s1[0]+s2[0];
      return TRUE;
    }
    else if(s1[0]<MIXSIZE&&(s1[0]+s2[0]>MIXSIZE))
    {
        printf("fgsd\n");
        for(int i=1;i<=s1[0];i++)
        {
            *s3[i]=s1[i];
        }
        for(int i=s1[0]+1,j=1;(void)(i<=MIXSIZE),j<=MIXSIZE-s1[0];j++,i++)
        {
            *s3[i]=s2[j];
        }
        *s3[0]=MIXSIZE;
      return FALSE;
    }
    else
    {
        for(int i=1;i<=MIXSIZE;i++)
        {
            *s3[i]=s1[i];
        }
        *s3[0]=MIXSIZE;
      return FALSE;
    }

}

求子串:

void SubString(SString *s3,SString s1,int pos,int len)
{
    if(pos<1||len>s1[0]||len<0||len>s1[0]-pos+1)
        printf("非法操作!\n");
    for(int i=1,j=pos;(void)(i<len),j<pos+len-1;i++,j++)
    {
        *s3[i]=s1[j];

    }
    *s3[0]=len;
}

串的堆分配存储表示

#include<stdio.h>
#include <stdlib.h>
#include<string.h>

typedef struct
{
    char *ch;
    int length;
}HString;
//将字符串chars复制到字符串T中
void StrAssign(HString *T,char *chars)
{
    int len = 0;
    while(*(chars+len)!='\0')  //计算串的长度
    {
        len++;
    }
    if(len==0)    //串chars为空的情况
    {
        T->ch=NULL;
        T->length=0;
    }
    else
    {
        T->ch=(char *)malloc(len * sizeof(char));
        for(int i=0;i<len;i++)
        {
           T->ch[i]=*(chars+i);
        }
        T->length=len;
    }
}
//打印串T元素
void Print_str(HString *T )
{
    int i=0;
    while(i<T->length)
    {
        printf("%c",T->ch[i++]);
    }
    printf("\n");
}
//返回串长度
int StrLength(HString *T)
{
    return T->length;
}
//比较两串
int StrCompare(HString *T,HString *S )
{
    int i;
    if(T->length!=S->length)
    {
        if(T->length>S->length)
        {
            printf("字符串不等,s1的长度大于s2\n");
            return 1;
        }
        else
        {
            printf("字符串不等,s1的长度小于s2\n");
            return -1;
        }
    }
    else
    {
        for(i=0;i<T->length;i++)
        {
            if(T->ch[i]>S->ch[i])
            {
                printf("长度相等,但s1>s2\n");
                return 1;
            }
            else if(T->ch[i]<S->ch[i])
            {
                printf("长度相等,但s1>s2\n");
                return -1;
            }

        }
        printf("字符串相等\n");
        return 0;
    }

}
//连接两的字符串
void Concat(HString *T,HString *s1,HString *s2)
{
    T->ch=(char *)malloc((s1->length+s2->length)*sizeof(char));
    if(!T->ch)
        exit(0);
    for(int i=0;i<s1->length;i++)
    {
        T->ch[i]=s1->ch[i];
    }
    for(int i=s1->length,j=0;i<s1->length+s2->length;i++,j++)
    {
        T->ch[i]=s2->ch[j];
    }
    T->length=s1->length+s2->length;
}
//求子串
void SubString(HString *T,HString *S,int pos,int len)
{
    T->ch=(char *)malloc(len*sizeof(char));
    if(!T->ch)
        exit(0);
    for(int i=pos-1,j=0;i<pos+len;i++,j++)
    {
        T->ch[j]=S->ch[i];
    }
    T->length=len;
}
//清空串
void ClearString(HString *T )
{
    if(T->ch)
    {
        free(T->ch);T->ch=NULL;
    }
    T->length=0;
}
//主函数,可对函数进行测试
int main()
{
    char s1[100];
    char s2[100];
    printf(" 请输入字符串s1:\n");
    gets(s1);
    printf("请输入字符串s2:\n");
    gets(s2);

    HString S,S1,S2,*p,*p1,*p2;
    p=&S; p1=&S1; p2=&S2;
    StrAssign(p1, s1);
    //StrAssign(p2, s2);
    //StrCompare(p1, p2);
    //Concat(p, p1, p2);
    //SubString(p, p1, 2, 4);

    //Print_str(p1);
    //ClearString(p1);
    //Print_str(p1);
}

串的模式匹配算法

1、传统算法

int  Index(HString *T,HString *S, int pos)
{
    int j=0;
    while(pos<T->length&&j<S->length)
    {
        if(T->ch[pos]==S->ch[j])
        {
            pos++;j++;
        }
        else
        {
            pos=pos-j+2;
            j=1;
        }
    }
    if(j>=S->length)
    {
        int len;
        len=pos-S->length+1;
        printf("%d",len);
        return len;
    }
    else
    {
       return 0;
    }
}
01-20 06:43