[C语言] 模拟strstr

模拟strstr

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <assert.h>
char* my_strstr(char* str1, char* str2)
{
  assert(str1 && str2);
  char* s1 = NULL;
  char* s2 = NULL;
  char* cp = str1;         //回溯
  if(*str2 == '\0')
  {
    return str1;
  }
  while (*cp)    
  {
    s1 = cp;
    s2 = str2;
    while ((*s1 == *s2) && *s1 && *s2)
    {
      s1++;
      s2++;
    }
    if (*s2 == '\0')     
    {
      return cp;
    }
    cp++;
  }
}

int main()
{
  char* p = "abbbccc";
  char* q = "bbc";
  char* ret = my_strstr(p, q);
  if(ret == NULL)
  {
    printf("not find");
  }
  else
  {
    printf("%s",ret);
  }
  return 0;
}