从1....n中随机输出m个不重复的数

void knuth(int n, int m) {
	srand((unsigned) time( NULL));
	for (int i = 0; i < n && m; i++) {
		//满足限定条件:rand() % (n - i) < m,即输出i,i递增不重复
		if (rand() % (n - i) < m) {
			cout << i << "\t";
			m--;
		} // end if
	} //end for
	return;
}