001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.text.similarity; 018 019import java.util.Objects; 020 021/** 022 * Represents the intersection result between two sets. 023 * 024 * <p>Stores the size of set A, set B and the intersection of A and B 025 * ({@code |A ∩ B|}).</p> 026 * 027 * <p>This class is immutable.</p> 028 * 029 * @since 1.7 030 * @see <a href="https://en.wikipedia.org/wiki/Intersection_(set_theory)">Intersection</a> 031 */ 032public class IntersectionResult { 033 /** 034 * The size of set A. 035 */ 036 private final int sizeA; 037 /** 038 * The size of set B. 039 */ 040 private final int sizeB; 041 /** 042 * The size of the intersection between set A and B. 043 */ 044 private final int intersection; 045 046 /** 047 * Create the results for an intersection between two sets. 048 * 049 * @param sizeA the size of set A ({@code |A|}) 050 * @param sizeB the size of set B ({@code |B|}) 051 * @param intersection the size of the intersection of A and B ({@code |A ∩ B|}) 052 * @throws IllegalArgumentException if the sizes are negative or the intersection is greater 053 * than the minimum of the two set sizes 054 */ 055 public IntersectionResult(final int sizeA, final int sizeB, final int intersection) { 056 if (sizeA < 0) { 057 throw new IllegalArgumentException("Set size |A| is not positive: " + sizeA); 058 } 059 if (sizeB < 0) { 060 throw new IllegalArgumentException("Set size |B| is not positive: " + sizeB); 061 } 062 if (intersection < 0 || intersection > Math.min(sizeA, sizeB)) { 063 throw new IllegalArgumentException("Invalid intersection of |A| and |B|: " + intersection); 064 } 065 this.sizeA = sizeA; 066 this.sizeB = sizeB; 067 this.intersection = intersection; 068 } 069 070 /** 071 * Get the size of set A. 072 * 073 * @return |A| 074 */ 075 public int getSizeA() { 076 return sizeA; 077 } 078 079 /** 080 * Get the size of set B. 081 * 082 * @return |B| 083 */ 084 public int getSizeB() { 085 return sizeB; 086 } 087 088 /** 089 * Get the size of the intersection between set A and B. 090 * 091 * @return {@code |A ∩ B|} 092 */ 093 public int getIntersection() { 094 return intersection; 095 } 096 097 @Override 098 public boolean equals(final Object o) { 099 if (this == o) { 100 return true; 101 } 102 if (o == null || getClass() != o.getClass()) { 103 return false; 104 } 105 final IntersectionResult result = (IntersectionResult) o; 106 return sizeA == result.sizeA && sizeB == result.sizeB && intersection == result.intersection; 107 } 108 109 @Override 110 public int hashCode() { 111 return Objects.hash(sizeA, sizeB, intersection); 112 } 113 114 @Override 115 public String toString() { 116 return "Size A: " + sizeA + ", Size B: " + sizeB + ", Intersection: " + intersection; 117 } 118}