| /** |
| * 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. |
| */ |
| package org.apache.hadoop.examples.pi.math; |
| |
| import org.apache.hadoop.examples.pi.Util; |
| |
| /** An arithmetic progression */ |
| public class ArithmeticProgression implements Comparable<ArithmeticProgression> { |
| /** A symbol */ |
| public final char symbol; |
| /** Starting value */ |
| public final long value; |
| /** Difference between terms */ |
| public final long delta; |
| /** Ending value */ |
| public final long limit; |
| |
| /** Constructor */ |
| public ArithmeticProgression(char symbol, long value, long delta, long limit) { |
| if (delta == 0) |
| throw new IllegalArgumentException("delta == 0"); |
| |
| this.symbol = symbol; |
| this.value = value; |
| this.delta = delta; |
| this.limit = limit; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) |
| return true; |
| else if (obj != null && obj instanceof ArithmeticProgression) { |
| final ArithmeticProgression that = (ArithmeticProgression)obj; |
| if (this.symbol != that.symbol) |
| throw new IllegalArgumentException("this.symbol != that.symbol, this=" |
| + this + ", that=" + that); |
| return this.value == that.value |
| && this.delta == that.delta |
| && this.limit == that.limit; |
| } |
| throw new IllegalArgumentException(obj == null? "obj == null": |
| "obj.getClass()=" + obj.getClass()); |
| } |
| |
| /** Not supported */ |
| public int hashCode() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public int compareTo(ArithmeticProgression that) { |
| if (this.symbol != that.symbol) |
| throw new IllegalArgumentException("this.symbol != that.symbol, this=" |
| + this + ", that=" + that); |
| if (this.delta != that.delta) |
| throw new IllegalArgumentException("this.delta != that.delta, this=" |
| + this + ", that=" + that); |
| final long d = this.limit - that.limit; |
| return d > 0? 1: d == 0? 0: -1; |
| } |
| |
| /** Does this contain that? */ |
| boolean contains(ArithmeticProgression that) { |
| if (this.symbol != that.symbol) |
| throw new IllegalArgumentException("this.symbol != that.symbol, this=" |
| + this + ", that=" + that); |
| if (this.delta == that.delta) { |
| if (this.value == that.value) |
| return this.getSteps() >= that.getSteps(); |
| else if (this.delta < 0) |
| return this.value > that.value && this.limit <= that.limit; |
| else if (this.delta > 0) |
| return this.value < that.value && this.limit >= that.limit; |
| } |
| return false; |
| } |
| |
| /** Skip some steps */ |
| long skip(long steps) { |
| if (steps < 0) |
| throw new IllegalArgumentException("steps < 0, steps=" + steps); |
| return value + steps*delta; |
| } |
| |
| /** Get the number of steps */ |
| public long getSteps() { |
| return (limit - value)/delta; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public String toString() { |
| return symbol + ":value=" + value + ",delta=" + delta + ",limit=" + limit; |
| } |
| |
| /** Convert a String to an ArithmeticProgression. */ |
| static ArithmeticProgression valueOf(final String s) { |
| int i = 2; |
| int j = s.indexOf(",delta="); |
| final long value = Util.parseLongVariable("value", s.substring(2, j)); |
| i = j + 1; |
| j = s.indexOf(",limit="); |
| final long delta = Util.parseLongVariable("delta", s.substring(i, j)); |
| i = j + 1; |
| final long limit = Util.parseLongVariable("limit", s.substring(i)); |
| return new ArithmeticProgression(s.charAt(0), value, delta, limit); |
| } |
| } |