Here you can find the source of binarySearchLower(int[] theSearchBase, int theLowerBound, int theUpperBound, int theKey)
| Parameter | Description |
|---|---|
| theSearchBase | An array of sorted integers from lowest <code>theSearchBase[0]</code> to highest <code>theSearchBase[theSearchBase.length]</code>. |
| theLowerBound | The low index bound of theSearchBase to search in. This allows the search to be focused to a predefined part of theSearchBase array. |
| theUpperBound | The high index bound of theSearchBase to search in. This allows the search to be focused to a predefined part of theSearchBase array. |
| theKey | The integer to search for. |
public static int binarySearchLower(int[] theSearchBase, int theLowerBound, int theUpperBound, int theKey)
//package com.java2s; /*//from ww w . j ava2 s. co m * #%L * org.bml * %% * Copyright (C) 2006 - 2014 Brian M. Lima * %% * This file is part of ORG.BML. * * ORG.BML is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * ORG.BML is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with ORG.BML. If not, see <http://www.gnu.org/licenses/>. * #L% */ public class Main { /** * An extension of the standard binary search that returns the next lowest * Integer in an array if the passed key does not exist in the array. If the * key does exist in the array it is returned. * * @param theSearchBase An array of sorted integers from lowest * <code>theSearchBase[0]</code> to highest * <code>theSearchBase[theSearchBase.length]</code>. * @param theLowerBound The low index bound of theSearchBase to search in. * This allows the search to be focused to a predefined part of * theSearchBase array. * @param theUpperBound The high index bound of theSearchBase to search in. * This allows the search to be focused to a predefined part of * theSearchBase array. * @param theKey The integer to search for. * @return the nearest low integer to theKey */ public static int binarySearchLower(int[] theSearchBase, int theLowerBound, int theUpperBound, int theKey) { //Argument sanity checking. if (theSearchBase == null) { throw new IllegalArgumentException("Can not operate on a null search base."); } else if (theSearchBase.length < 2) { throw new IllegalArgumentException("Can not operate on a search base with a length of less than 2."); } else if (theLowerBound > theUpperBound) { throw new IllegalArgumentException( "Can not operate when the lower bound is greater than the lower bound."); } else if (theLowerBound == theUpperBound) { throw new IllegalArgumentException("Can not operate when the lower bound is equal to the lower bound."); } int comparisonCount = 1, // counting the number of comparisons (optional) lowerbound = theLowerBound, upperbound = theUpperBound, position = (lowerbound + upperbound) / 2; // find the subscript of the middle position. while ((theSearchBase[position] != theKey) && (lowerbound <= upperbound)) { comparisonCount++; if (theSearchBase[position] > theKey) { // If the number is > key, .. upperbound = position - 1; // decrease position by one. } else { lowerbound = position + 1; // Else, increase position by one. } position = (lowerbound + upperbound) / 2; } return theSearchBase[lowerbound - 1]; } /** * An extension of the standard binary search that returns the next lowest * Integer in an array if the passed key does not exist in the array. If the * key does exist in the array it is returned. * * @param theSearchBase An array of sorted integers from lowest * <code>theSearchBase[0]</code> to highest * <code>theSearchBase[theSearchBase.length]</code>. * @param theLowerBound The low index bound of theSearchBase to search in. * This allows the search to be focused to a predefined part of * theSearchBase array. * @param theUpperBound The high index bound of theSearchBase to search in. * This allows the search to be focused to a predefined part of * theSearchBase array. * @param theKey The integer to search for. * @return the nearest low integer to theKey */ public static Integer binarySearchLower(final Integer[] theSearchBase, final int theLowerBound, final int theUpperBound, final int theKey) { //Argument sanity checking. if (theSearchBase == null) { throw new IllegalArgumentException("Can not operate on a null search base."); } else if (theSearchBase.length < 2) { throw new IllegalArgumentException("Can not operate on a search base with a length of less than 2."); } else if (theLowerBound > theUpperBound) { throw new IllegalArgumentException( "Can not operate when the lower bound is greater than the lower bound."); } else if (theLowerBound == theUpperBound) { throw new IllegalArgumentException("Can not operate when the lower bound is equal to the lower bound."); } int comparisonCount = 1, // counting the number of comparisons (optional) lowerbound = theLowerBound, upperbound = theUpperBound, position = (lowerbound + upperbound) / 2; // find the subscript of the middle position. while ((theSearchBase[position] != theKey) && (lowerbound <= upperbound)) { comparisonCount++; if (theSearchBase[position] > theKey) { // If the number is > key, .. upperbound = position - 1; // decrease position by one. } else { lowerbound = position + 1; // Else, increase position by one. } position = (lowerbound + upperbound) / 2; } return theSearchBase[lowerbound - 1]; } }