定义块对象

class Block{private int start;private int end;private int maxKey;public Block(int start, int end, int maxKey) {this.start = start;this.end = end;this.maxKey = maxKey;}public int getStart() {return start;}public void setStart(int start) {this.start = start;}public int getEnd() {return end;}public void setEnd(int end) {this.end = end;}public int getMaxKey() {return maxKey;}public void setMaxKey(int maxKey) {this.maxKey = maxKey;}

        基于Block对象的分块查找算法

package SearchExercise20240723;
import java.util.Arrays;
import java.util.Scanner;
public class SearchExercise5 {public static void main(String[] args) {Scanner sc = new Scanner(System.in);System.out.println("需要多大的数组?");int size = sc.nextInt();int[] array = new int[size];for (int i = 0; i < array.length; i++) {System.out.printf("请输入第%d个元素", i + 1);array[i] = sc.nextInt();}// 创建索引表int blockSize = (int)Math.sqrt(array.length);Block[] blocksArray = creatBlocksArray(array, blockSize);// 分块查找System.out.println("请输入要查找的元素");int key = sc.nextInt();int result = blockSearch(array, blocksArray, key);if (result == -1) {System.out.println("数组中无法找到该元素");} else {System.out.printf("成功找到，下标是%d", result);}}public static Block[] creatBlocksArray(int[] array, int blockSize) {int blockNumbers = (int)Math.ceil(array.length * 1.0 / blockSize);Block[] blockArray = new Block[blockNumbers];for (int i = 0; i < blockArray.length; i++) {int start = i * blockSize;int end = Math.min(start + blockSize, array.length);int maxKey = Arrays.stream(array, start, end).max().orElse(Integer.MIN_VALUE);blockArray[i] = new Block(start, end, maxKey);}return blockArray;}public static int blockSearch(int[] array, Block[] blocksArray, int key) {int blockIndex = -1;for (int i = 0; i < blocksArray.length; i++) {if (key <= blocksArray[i].getMaxKey()) {blockIndex = i;break;}}if (blockIndex == -1) {return -1;}int start = blocksArray[blockIndex].getStart();int end = blocksArray[blockIndex].getEnd();for (int i = start; i < end; i++) {if(array[i] == key){return i;}}return -1;}
}class Block{private int start;private int end;private int maxKey;public Block(int start, int end, int maxKey) {this.start = start;this.end = end;this.maxKey = maxKey;}public int getStart() {return start;}public void setStart(int start) {this.start = start;}public int getEnd() {return end;}public void setEnd(int end) {this.end = end;}public int getMaxKey() {return maxKey;}public void setMaxKey(int maxKey) {this.maxKey = maxKey;}
}