/**
* Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.linkedin.pinot.tools.scan.query;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class Utils {
public static List<List<Object>> cartesianProduct(List<List<Object>> lists) {
int numElements = 1;
for (int i = 0; i < lists.size(); i++) {
numElements *= lists.get(i).size();
}
List<List<Object>> result = new ArrayList<>();
for (int i = 0; i < numElements; i++) {
int j = 1;
List<Object> oneSet = new ArrayList<>();
for (List<Object> list : lists) {
int index = (i / j) % list.size();
oneSet.add(list.get(index));
j *= list.size();
}
result.add(oneSet);
}
return result;
}
public static void main(String[] args) {
List<List<Object>> test = new ArrayList<>();
List<Object> list1 = new ArrayList<Object>();
list1.addAll(Arrays.asList(1, 2, 3));
test.add(list1);
List<Object> list2 = new ArrayList<Object>();
list2.addAll(Arrays.asList(9));
test.add(list2);
List<Object> list3 = new ArrayList<Object>();
list3.addAll(Arrays.asList(4, 5));
test.add(list3);
for (List<Object> list : cartesianProduct(test)) {
for (Object object : list) {
System.out.print(object + " ");
}
System.out.println();
}
}
}