数据结构 --- 串

工程目录结构:

common.h:

//#ifndef __common_h__
//#define __common_h__

#define OK 1
#define ERROR 0
#define TRUE 1
#define FALSE 0 

#define MAXSIZE 20

typedef int Status;        //函数的返回结果，OK、ERREO、TRUE、FALSE
typedef int ElemType;   //结点数据域的数据类型

//#endif

common.c:

#include "common.h"

Status visit(ElemType e)
{
    printf("%d , ", e);
    return OK;
}

String.h:

typedef char String[MAXSIZE + 1];   // 0 号位存储串的长度

String.c:

#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include "common.h"
#include "String.h"

void InitString(String Str)
{
    Str[0] = 0;
}

//生成一个其值等于chars的串 Str
Status StringAssign(String Str, char *chars)
{
    if (strlen(chars) > MAXSIZE)
        return ERROR;
    Str[0] = strlen(chars);
    for (int i = 1; i <= Str[0]; ++i)
        Str[i] = *(chars + i - 1);

    return OK;
}

//由串oldStr复制得串newStr
Status CopyString(String newStr, String oldStr)
{
    for (int i = 0; i <= oldStr[0]; ++i)
        newStr[i] = oldStr[i];
    return OK;
}

Status EmptyString(String Str)
{
    if (Str[0] == 0)
        return TRUE;
    else
        return FALSE;
}

//前提是: str1 和 str2 均不为空串
// 0: str1 == str2  正数: str1 > str2  负数: str1 < str2   
int CompareString(String str1, String str2)
{
    for (int i = 1; i <= str1[0] && i <= str2[0]; ++i)
    {
        if (str1[i] != str2[i])
            return str1[i] - str2[i];
    }
    return str1[0] - str2[0];
}

int StringLength(String Str)
{
    return Str[0];
}

Status StringClear(String Str)
{
    Str[0] = 0;
    return OK;
}

//用T返回S1和S2联接而成的新串。若未截断，则返回TRUE，否则FALSE
Status StringConcat(String T, String S1, String S2)
{
    int i;
    if (S1[0] + S2[0] <= MAXSIZE)  //未截断
    {
        for (i = 1; i <= S1[0]; ++i)
            T[i] = S1[i];

        for (i = 1; i <= S2[0]; ++i)
            T[S1[0] + i] = S2[i];

        T[0] = S1[0] + S2[0];

        return FALSE;
    }
    else    //截断,按照这里定义的String，截断也是截断S2
    {
        for (i = 1; i <= S1[0]; ++i)
            T[i] = S1[i];

        for (i = 1; i <= MAXSIZE - S1[0]; ++i)
            T[S1[0] + i] = S2[i];

        T[0] = MAXSIZE;

        return TRUE;
    }
}

//用Sub返回串S的第pos个字符起长度为len的子串
Status SubString(String sub, String S, int pos, int len)
{
    if (pos < 1 || pos > S[0] || len < 0 || len > S[0] - pos + 1)
        return FALSE;

    for (int i = 1; i <= len; ++i)
        sub[i] = S[pos + i - 1];

    sub[0] = len;

    return TRUE;
}

//返回子串T在主串S中第pos个字符之后的位置。若不存在,则函数返回值为0。 
//其中,T非空,1≤pos≤StrLength(S)。
int Index(String S, String T, int pos)
{
    int i = pos,   //主串开始匹配的位置
        j = 1;       //子串匹配的索引

    while (i <= S[0] && j <= T[0])
    {
        if (S[i] == T[j])
        {
            ++i;
            ++j;
        }
        else
        {
            i = i - j + 1 + 1;  //j可以间接用来记录i++的次数，通过简单的计算即可转换为i下一次匹配的位置
            j = 1;
        }
    }

    if (j > T[0])
        return i - T[0];
    else
        return 0;
}

/*  T为非空串。若主串S中第pos个字符之后存在与T相等的子串， */
/*  则返回第一个这样的子串在S中的位置，否则返回0 */
int Index2(String S, String T, int pos)
{
    if (pos > 0)
    {
        int lenS = S[0];
        int lenT = T[0];
        int i = pos;
        String sub;
        while (i <= lenS - lenT + 1)
        {
            /* 取主串中第i个位置长度与T相等的子串给sub */
            SubString(sub, S, i, lenT);
            if (CompareString(sub, T) != 0)
                ++i;
            else
                return i;
        }
    }
    return 0;
}

//输出串
void StringPrint(String Str)
{
    for (int i = 1; i <= Str[0]; ++i)
        printf("%c", Str[i]);
    printf("
");
}

void StringStart()
{
    String Str;
    InitString(Str);
    printf("创建字符串  str = ABCDEFG
");
    char chars[] = "ABCDEFG";
    if (OK == StringAssign(Str, chars))
        printf("
字符串创建成功!
");
    else
        printf("
字符串创建失败!
");

    printf("
Str= ");
    StringPrint(Str);

    printf("
Str 的长度: %d
", StringLength(Str));

    String NewStr;
    InitString(NewStr);

    if (EmptyString(NewStr) == TRUE)
        printf("
NewStr 是空串!
");
    else
        printf("
NewStr 不是空串!
");

    CopyString(NewStr, Str);

    printf("
复制穿 Str -> NewStr, NewStr = ");
    StringPrint(NewStr);

    if (EmptyString(NewStr) == TRUE)
        printf("
NewStr 是空串!
");
    else
        printf("
NewStr 不是空串!
");

    printf("
NewStr 的长度: %d
", StringLength(NewStr));

    String Str1, Str2, Str3;
    InitString(Str1);
    InitString(Str2);
    char chars1[] = "ABCDEFABCDEGHHIJKLMN";
    char chars2[] = "1234567891011121314";
    char chars3[] = "ABCDE";
    StringAssign(Str1, chars1);
    StringAssign(Str2, chars2);
    StringAssign(Str3, chars3);

    printf("
Str1 = ");
    StringPrint(Str1);
    printf("Str2 = ");
    StringPrint(Str2);
    printf("Str3 = ");
    StringPrint(Str3);

    if (0 == CompareString(Str1, Str))
        printf("
Str1 == Str");
    else if (CompareString(Str1, Str) > 0)
        printf("
Str1 > Str");
    else
        printf("
Str1 < Str");

    if (0 == CompareString(Str2, Str))
        printf("
Str2 == Str");
    else if (CompareString(Str2, Str) > 0)
        printf("
Str2 > Str");
    else
        printf("
Str2 < Str");

    if (0 == CompareString(Str3, Str))
        printf("
Str3 == Str");
    else if (CompareString(Str3, Str) > 0)
        printf("
Str3 > Str");
    else
        printf("
Str3 < Str");

    String T;
    if (StringConcat(T, Str1, Str2) == TRUE)
        printf("

Str2 被截断!
");
    else
        printf("

Str2 未被截断!
.");

    printf("
T = ");
    StringPrint(T);

    String sub;

    printf("
从T中第7个位置开始，截取长度为5的 Sub, Sub = ");
    if (SubString(sub, T, 7, 5) == TRUE)
        StringPrint(sub);

    String Str5;
    char chars5[] = "HIJ";
    StringAssign(Str5, chars5);
    int pos = 3;

    int index = Index(Str1, Str5, pos);
    printf("

Str5 = ");
    StringPrint(Str5);
    printf("
Str5在Str1中的位置是: %d
", index);

    pos = Index2(Str1, Str3, 2);
    printf("
Str1中，从第二个位置开始，与Str3相等的子串的 Pos = %d
", pos);
    printf("
");
}

main.c:

int main()
{
    //LinkListStart();
    //StackStart();
    //LinkStackStart();
    //StartQueue();
    //LinkQueueStart();
    StringStart();
    getchar();
    return 0;
}