子字符串查找----暴力查找法

public static int search(String pat, String txt) {
	int M = pat.length();
	int N = txt.length();
	for(int i = 0;i<= N;i++) {
		int j;
		for(j=0;j<M;j++)
			if(txt.charAt(i+j)!=pat.charAt(j))
				break;
		if(j==M)	return i;
	}
	return N;
}

public static int Search(String pat,String txt) {
	int j, M = pat.length();
	int i, N = txt.length();
	for(i=0,j=0;i<N&&j<M;i++) {
		if(txt.charAt(i)==pat.charAt(j))	j++;
		else {i-=j;j=0;}
	}
	if(j==M)	return i-M;
	else	return N;
}