Here you can find the source of powerX(long a, long b)
public static long powerX(long a, long b)
//package com.java2s; /*//w w w . ja va 2 s . c o m * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to you 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. */ public class Main { /** Cheap, unsafe, long power. power(2, 3) returns 8. */ public static long powerX(long a, long b) { long x = 1; while (b > 0) { x *= a; --b; } return x; } }