C和指针第六章课后题

#include <stdio.h>int del_substr(char *str, char const *substr);int main(void)
{
    char src[] = "ABCDEFG";
    //char *substr = "FGH";
    char *substr = "CDE";
 
    int ret = 0;
    ret = del_substr(src, substr);
    printf("ret = %d\n", ret);
    printf("%s\n", src);
 
    return 0;
}
 
int del_substr(char *str, char const *substr)
{
    char *t_str = str;
    char const *t_substr = substr;
    int flag = 0;
 
    char *find_str = NULL;
 
    //查找子串
    while (*t_str)
    {
        if (*t_str == *t_substr)
        {
 
            if (find_str == NULL)
            {
                find_str = t_str;  //指向第一次出现子串的位置
            }
 
            t_substr++;
            if (*t_substr == '\0') //找到目标子串
            {
                break;
            }
        }
        else
        {
            t_substr = substr; //复位指针
            find_str = NULL;
        }
 
        t_str++;
    }

    if (find_str == NULL)
    {
        flag = 0;
    }
    else
    {
        flag = 1;
        //进行删除除子串
 
        while (*t_str)
        {
            t_str++;
            *find_str = *t_str; //将后面的字符赋值过来
 
            find_str++;
        }
 
    }

    return flag;
}