java二分法查找

import java.util.Arrays;public class Hello {public static void main(String[] args) {int[] arr = { 11, 55, 88, 111, 25, 67, 78, 95, 99, 66, 77, 33, 44, 22, 66 };int searchWord = 55; // 所要查找的数System.out.printf("普通循环查找%d的次数是%d", searchWord, genetalLoop(arr, searchWord));System.out.printf("二分法查找%d的次数是%d", searchWord, binarySearch(arr, searchWord));}/** * 普通方法 * @param arr 数组 * @param searchWord 查询的数 * @return */static int genetalLoop(int[] arr, int searchWord) {int searchCount = 0;for (int i = 0; i < arr.length; i++) {searchCount++;if (searchWord == arr[i])break;}return searchCount;}/** * 二分法 * @param arr 数组 * @param searchWord 查询的数 * @return */static int binarySearch(int[] arr, int searchWord) {Arrays.sort(arr); // 先对传进来的数组进行排序System.out.println("\n" + Arrays.toString(arr));// 二分法查找int iIndex = 0; // 相当于指针的东西int iStart = 0;int iEnd = arr.length - 1;int searchCount = 0;for (int i = 0; i < arr.length / 2; i++) {searchCount++;iIndex = (iStart + iEnd) / 2;if (arr[iIndex] < searchWord) {System.out.println("大了");iStart = iIndex;} else if (arr[iIndex] > searchWord) {System.out.println("小了");iEnd = iIndex;} else {break;}}return searchCount;}}