C/C++查找子串
#define _CRT_SECURE_NO_WARNINGS
#include<>
#include<>
#include<>
//优化思路 memcmp(str,substr,3)==0
int myStrstr(char*str, char*subStr)
{
int num = 0;
while (*str!='\0')
{
if (*str != *subStr)
{
str++;
num++;
continue;
}
//创建临时指针
char*tmpStr = str;
char*tmpSubStr = subStr;
while (*tmpSubStr!='\0')
{
if (*tmpStr != *tmpSubStr)
{
//匹配失败
str++;
num++;
break;
}
tmpStr++;
tmpSubStr++;
}
if (*tmpSubStr == '\0')
{
//匹配成功
return num;
}
}
return - 1;
}
void test01()
{
char*str = "abcdefgdnf";
int ret = myStrstr(str, "dnf");
if (ret == -1)
{
printf("未找到子串\n");
}
else
{
printf("找到了子串，位置为：%d\n",ret);
}
}
int main()
{
test01();
return EXIT_SUCCESS;
}