C语言 查找字符串

输入一个字符串，并查找子字符串.

#include <stdio.h>
#include <string.h>
int search(char str[],char  word[])
{
 int length = strlen(word);
 int i = 0, j = 0, num = 0;
 while(str[i + length-1] != '\0') {
  for (j = 0; j < length; j++) {
   if (str[i + j] != word[j])
    break;
  }
  if (j == length) {
   num++;
   i += length;
  }
  else
   i++;
 }
 return num;
}
int main()
{
 char str[100] = { '\0' };
 char word[10] = { '\0' };
 int num = 0;
 gets(str);
 gets(word);
 num = search(str, word);
 printf("%d", num);
 return 0;
}