C语言字符串的拼接和暴力匹配

//动态存储字符串 （堆分配）
#include <stdio.h>
#include <stdlib.h>

typedef struct {
    char *ch;
    int length;
}HString;

//初始化
HString* InitString()
{
    HString* str = (HString *)malloc(sizeof(HString));
    str->ch = NULL;
    str->length = 0;
    return str;
}

//赋值操作
void StrAssign(HString* S,char* str)
{
    int len = 0;
    char* temp = str;
    while (*temp != '\0') //查找str的长度用len保存
    {
        len++;
        temp++;
    }
    if(len == 0)
    {
        printf("赋值不合法\n");
        return;
    }
    temp = str; //temp指针回到开始位置
    S->ch = (char *)malloc(sizeof(char) * (len + 1));
    for (int i = 0; i < len; ++i) {
        S->ch[i] = *temp;
        temp++;
        S->length++;
    }
}

// 字符串的拼接 把T拼接到S后面
void ConCat(HString* S,HString* T)
{
    int m = 0;
    int n = 0;

    char* lens = S->ch;
    char* lent = T->ch;
    while (*lens != '\0')
    {
        m++;
        lens++;
    }
    m++;
    while (*lent != '\0')
    {
        S->ch[m] = T->ch[n];
        n++;
        m++;
        lent++;
    }

    printf("拼接后的结果为:");
    for (int i = 0; i < m; ++i) {
        printf("%c",S->ch[i]);
    }
    printf("拼接后的长度为;%d\n",m);
}

//打印输出字符串
void ShowString(HString* S)
{
    if(S->ch == NULL)
    {
        printf("字符串是空串！\n");
        return;
    }
    for (int i = 0; i < S->length; ++i) {
        printf("%c ",S->ch[i]);
    }
    printf("字符串的长度为:%d\n",S->length);
}
// 暴力匹配 S为主串 T为模式串
void ForceMather(HString* S,HString* T)
{
    int i = 0;
    int j = 0;
    while (i < S->length && j < T->length)
    {
        if(S->ch[i] == T->ch[j]){
            i++;
            j++;
        }
        else{
            i = i - j + 1;
            j = 0;
        }
    }
    if( j == T->length)
    {
        printf("匹配成功，在主串中出现的位置为:%d\n",i - j);
    }
    else{
        printf("匹配失败！\n");
    }
}
int main()
{
    HString* string1 = InitString();
    HString* string2 = InitString();
    StrAssign(string1,"hello world");
    StrAssign(string2,"wo");
    ShowString(string1);
    ShowString(string2);
    //ConCat(string1,string2);
    ForceMather(string1,string2);
    return 0;
}

标签：ch,++,HString,C语言,int,length,拼接,printf,字符串
来源： https://blog.csdn.net/junfuyou/article/details/119462025