public boolean isSubset(String s1, String s2) {
		int[] c1=new int[26], c2=new int[26];
		for (char c:s1.toCharArray()) 
			++c1[c-'a'];
		for (char c:s2.toCharArray())
			++c2[c-'a'];
		for (int i=0;i<26;++i) 
			if (c1[i]<c2[i]) return false;
		return true;
	}