src/main/java/org/vanilladb/bench/util/RandomNonRepeatGenerator.java
public int next() {
//		int rndIndex = (int) ((array.length - 1 - curIndex) * rg.nextDouble())
//				+ curIndex;
//		int tmp = array[rndIndex];
//		array[rndIndex] = array[curIndex];
//		array[curIndex] = tmp;
//		curIndex++;
//
//		return tmp;
		int number;
		do{
			number = rg.nextInt(size) + 1;
		} while(!numberSet.add(number));
		
		return number;
	}
public int next() {
//		int rndIndex = (int) ((array.length - 1 - curIndex) * rg.nextDouble())
//				+ curIndex;
//		int tmp = array[rndIndex];
//		array[rndIndex] = array[curIndex];
//		array[curIndex] = tmp;
//		curIndex++;
//
//		return tmp;
		int number;
		do{
			number = rg.nextInt(size) + 1;
		} while(!numberSet.add(number));
		
		return number;
	}
Not repeat, randomly choose a number from 1 to the initinalized size