這樣 ?

# python
def isSubstring(s1, s2):
    return 1 if s1 in s2 else 0
# 自刻的話...
def isSubstring(s1, s2):
    if len(s1) > len(s2): return 0
    for i in range(len(s2)):
        for j in range(i, len(s2)):
            if s1 == s2[i:j+1]:
                return 1
    return 0

/** C */
int isSubstring(char* s1, char* 2)
{
    return strstr(s2, s1) != NULL ? 1 : 0;
}
/** C 找了範例直接改... */
int isSubstring(char *s1, char *s2)
{
    while (*s2) 
	{
	    char *Begin = s2;
		char *pattern = s1;
		    
		// If first character of sub string match, check for whole string
		while (*s2 && *pattern && *s2 == *pattern) 
		{
		    s2++;
			pattern++;
		}
		// If complete sub string match, return starting address 
		if (!*pattern)
			return 1;
		    	  
		s2 = Begin + 1;	// Increament main string 
	}
	return 0;
}

set "row" to s1
set length of s1 to len1
set "tomorrow" to s2
set length of s2 to len2
set 0 to result

if len1 > len2
   set 0 to result
else
   for i = 1 to len2-len1+1
      extract s2 range from char at position i to char at position (i+len1-1) to str
      if str equals to s1 then
         set 1 to result
      end if
   end for
end if

write result to output