C语言实现串的基本操作（复制，比较，插入，删除）

#include 
#include 
#include
#define TRUE 1
#define FALSE 0
#define OVERFLOW 1
#define MAX_SIZE 1024

typedef  int  Status;



/**
*串的顺序结构实现
typedef struct{
    char ch[MAX_SIZE+1];
    int length;
}SeqString;
*/

/**串的堆式顺序存储结构（Heap）*/
typedef struct{
    char * ch ;
    int length;
}HeapString;

void InitString(HeapString * str)
{
    str->ch = NULL;
    str->length = 0;
}
/**为串Str赋值*/
Status StrAssigh(HeapString *str,char * chars)
{
    int len = strlen(chars);
    InitString(str);
    str->ch = (char*)malloc(len * sizeof(char));
    if(!str->ch)
        exit(OVERFLOW);
    for(int i = 0;i < len;i++)
    {
        str->ch[i] = chars[i];
    }
    str->length = len;
    return 1;
}
void PrintString(HeapString * str)
{
    if(str->length == 0)
        printf("字符串为空！\n");
    for(int i = 0;i < str->length;i++)
    {
        printf("%c",str->ch[i]);
    }
}
Status StrCopy(HeapString * destStr,HeapString  * srcStr)
{
    InitString(destStr);
    destStr->ch = (char *)malloc(sizeof(char) * srcStr->length);
    for(int i = 0;i < srcStr->length;i++)
    {
        destStr->ch[i] = srcStr ->ch[i];
    }
    destStr->length = srcStr->length;
    return TRUE;

}
/**比较两个字符串的大小str1 == str2 返回0 ；str1 < str2 返回负数；str1 > str2 返回正数*/
Status StrCompare(HeapString * str1,HeapString * str2)
{
    for(int i = 0;i < str1->length && i < str2->length;i++)
    {
        //相等的字符跳过，直到不等的字符
        if(str1->ch[i] != str2->ch[i])
            return str1->ch[i] - str2->ch[i] ;//返回正数和负数

    }
    //字符都相等，比较字符串的长度
    return str1->length - str2->length;
}
Status Concat(HeapString *destStr,HeapString *str1,HeapString *str2)
{
    InitString(destStr);
    int len = str1->length + str2 ->length;
    destStr->ch = (char*)malloc(sizeof(char) * len);
    for(int i = 0;i < str1->length;i++)
    {
        destStr->ch[i] = str1->ch[i];
    }
    for(int i = 0;i< str2->length;i++)
    {
        destStr->ch[i+str1->length] = str2->ch[i];
    }
    destStr->length = len;
    return TRUE;
}
/**截取str字符串从pos位置len长度的字符到deststr中*/
Status  SubString(HeapString * deststr,HeapString *str,int pos,int len)
{
    InitString(deststr);
    deststr->ch = (char *)malloc(sizeof(char) * len);
    for(int i = 0;i < len;i++)
    {
        deststr->ch[i] = str->ch[i+pos-1];
    }
    deststr->length = len;
    return TRUE;
}
/**返回子串child在父串parent中的位置*/
int Index(HeapString * parent,HeapString * child)
{
    HeapString * str = (HeapString*)malloc(sizeof(HeapString));
    InitString(str);
    int len = child->length;
    int pos = 0;
    while(pos + len  <= parent ->length)
    {
        SubString(str,parent,pos+1,len);
        if(!StrCompare(str,child))
            return pos+1;
        pos++;
    }
    return FALSE;
}
/**从pos位置删除len个字符*/
Status StrDelete(HeapString * str,int pos ,int len)
{

    for(int i = pos-1;i < str->length - len;i++)
       str->ch[i] = str->ch[i+len];
    str->length = str->length - len;
    return TRUE;

}
/**在str中的pos位置插入字符串insertstr*/
Status StrInsert(HeapString * str ,int pos,HeapString * insetstr)
{
    int len = str->length + insetstr->length;

    str -> ch = (char*)realloc(str->ch,sizeof(char)*len);
    for(int i = len-1;i >= pos+insetstr->length-1 ;i--)
    {
        str->ch[i] = str->ch[i-1];
    }
    for(int i = 0;i < insetstr->length;i++)
    {
        str->ch[i + pos -1] = insetstr->ch[i];
    }
    str->length = len;
    return TRUE;

}
/**将str中的oldstr字符串替换成newstr字符串*/
Status Replace(HeapString *str,HeapString *oldstr,HeapString *newstr)
{
    int pos = Index(str,oldstr);
    StrDelete(str,pos,oldstr->length);
    StrInsert(str,pos,newstr);
    return TRUE;
}

int main()
{
    char chars[] = "abcdefg";
    HeapString  * str1  = (HeapString *)malloc(sizeof(HeapString));
    HeapString  * str2  = (HeapString *)malloc(sizeof(HeapString));
    HeapString  * str3  = (HeapString *)malloc(sizeof(HeapString));
    HeapString  * str4  = (HeapString *)malloc(sizeof(HeapString));
    HeapString  * str5  = (HeapString *)malloc(sizeof(HeapString));

    printf("str1:");
    StrAssigh(str1,chars);
    PrintString(str1);

    StrCopy(str2,str1);
    printf("\n复制后的str2:");
    PrintString(str2);

    StrAssigh(str3,"abccdesdf");
    printf("\nstr1与str3比较结果为：%d",StrCompare(str1,str3));

    Concat(str4,str1,str3);
    printf("\nstr1与str3连接后的字符串为：");
    PrintString(str4);

    SubString(str5,str1,2,3);
    printf("\n从str1中截取的字符串为：");
    PrintString(str5);

    printf("\nstr5在str1中的位置为：%d",Index(str1,str5));

    printf("\nstr1中从第2个位置删除3个字符:");
    StrDelete(str1,2,3);
    PrintString(str1);

    HeapString  * str6  = (HeapString *)malloc(sizeof(HeapString));
    StrAssigh(str6,"ABCD");
    printf("\nstr1中从第3个位置插入字符串ABCD:");
    StrInsert(str1,3,str6);
    PrintString(str1);


    printf("\nstr2中字符串bcd(str5)替换成str6:");
    Replace(str2,str5,str6);
    PrintString(str2);
    return 0;
}