Find substring (20 points) (c language version)

This question requires a simple function of the search string.

Function interface definition:
char * Search (S char *, char * T);

Substring search function to find the string s t, the return address of the first sub-string t in s. If not found, NULL is returned.

Sample testing procedures referees:
#include <stdio.h>
#define the MAXS 30

Search * char (S char *, char T);
void the ReadString (S char []); / ref provided, details are not list * /

int main ()
{
char s [Maxs], t [Maxs], * post;

ReadString(s);
ReadString(t);
pos = search(s, t);
if ( pos != NULL )
    printf("%d\n", pos - s);
else
    printf("-1\n");

return 0;

}

/ * Your code will be embedded here * /

Sample Input 1:
at The C Programming Language
RAM

Output Example 1:
10

Sample Input 2:
at The C Programming Language
here. Bored

Output Sample 2:
-1

char *search( char *s, char *t )
{
    int i, j, k;
	char *p = NULL;
    for (i = 0, j = 0; s[i] != '\0'; i++)
    {   
        k = i; j = 0;     
        // 不可以直接用i
        //初始化j， 保证t[j]每一次都是由第一个字母开始
        while (t[j] == s[k])
        {
            j++; k++;
            if (t[j] == '\0')
            {
            	p = &s[i];    //也可以直接return (s + i)
            	return p;
			}
        }
    }

    return p;
}