Java二分法查找数组元素

package chapter5;

import java.util.Random;

public class Array {
	public static int[] generateArray() {
		System.out.println("generate Array... ");
		int[] group500;
		group500 = new int[10];
		System.out.println("generate Array successful... ");
		System.out.println("the Array length is: " + group500.length);
		return group500;
	}

	public static int[] generateArray(int length) {
		System.out.println("generate Array... ");
		int[] group500;
		group500 = new int[length];
		System.out.println("generate Array successful... ");
		System.out.println("the Array length is: " + group500.length);
		return group500;
	}

	public static int[] setSortDate(int[] array) {
		System.out.println("the Array is:");
		for (int i = 1; i <= array.length; i++) {
			array[i - 1] = i;
			System.out.print(array[i] + " ");
		}
		return array;
	}
	public static int[] setSortDate(int[] array, int[] arrayData) {
		System.out.println("the Array is:");
		for (int i = 0; i < array.length; i++) {
			array[i] = arrayData[i];
			System.out.print(array[i] + " ");
		}
		return array;
	}

	public static int[] setRadomDate(int[] array) {
		System.out.println("the Array is:");
		for (int i = 0; i < array.length; i++) {
			array[i] = new Random().nextInt(array.length) + 1;
			for (int j = 0; j < i + 1; j++) {
				if ((i != j) && array[i] == array[j])
					array[i] = new Random().nextInt(array.length) + 1;
			}
		}
		for (int i = 0; i < array.length; i++) {
			System.out.print(array[i] + " ");
		}
		return array;
	}

	public static void sort(int[] array) {
		System.out.println();
		System.out.println("now we will sort it as 1~9:");

		for (int i = 0; i < array.length; i++) {
			// int k;
			int tmp;
			// k = i;
			for (int j = i + 1; j < array.length; j++) {
				if (array[i] > array[j]) {
					tmp = array[i];
					array[i] = array[j];
					array[j] = tmp;
				}
			}

		}
		System.out.println("now the result is: ");
		for (int i = 0; i < array.length; i++) {
			System.out.print(array[i] + " ");
		}
	}

	public static String search(int[] array, int beSearchedNum) {
		// TODO Auto-generated method stub
		System.out.println();
		System.out.println(beSearchedNum + " wanted be search!");
		System.out.println("now we will search its index");
		int min = 0;
		int max = array.length - 1;
		int mid = (int) ((min + max) / 2);
		int searchTimes = 0;
		int searchTimesMax = array.length;
		String result = null;
		String sorry = "Sorry, the system can't find ur Num!";
		if (array[min] <= beSearchedNum && array[max] >= beSearchedNum) {

			while (min <= max) {
				if (array[mid] == beSearchedNum) {
					result = "It is: " + mid;
					return result;
				} else if (array[mid] > beSearchedNum) {
					searchTimes++;
					max--;
				} else if (array[mid] < beSearchedNum) {
					searchTimes++;
					max++;
				}
				mid = (int) ((min + max) / 2);
				if (searchTimes == searchTimesMax) {
					result = sorry;
					break;
				}

			}
		} else {
			result = sorry;

		}
		return result;
	}
}

// 如果不使用集合，请仿照下面的写法
class ProduceRandom {
	public static void main(String[] args) {
		Integer[] intArray = getRandomArray(100, 200, 10);
		for (Integer i : intArray) {
			System.out.print(i + " ");
		}
	}

	/**
	 * @param MIN
	 *            :下界
	 * @param MAX
	 *            ：上界
	 * @param SUM
	 *            ：总个数
	 * @return：不同整数的整型数组
	 */
	public static Integer[] getRandomArray(final int MIN, final int MAX,
			final int SUM) {
		Integer[] intArray = new Integer[SUM];
		for (int counter = 0; counter < 10; counter++) { // 记录已经产生的随机数个数
			Integer temp = (int) (Math.random() * (MAX - MIN)) + MIN;// 假设只产生整数，不产生浮点数等其他类型的数
			int index = temp % SUM;// 因为没有使用集合，为了提高匹配效率，仿真哈希算法，简单的产生下标
			while (intArray[index] != null) {
				if (intArray[index] == temp)
					break;// 值相同时也复制到那个堆内存，相当于什么都没做
				index = (index + 1) % SUM;
			}
			intArray[index] = temp;
		}
		return intArray;
	}
}

package chapter5;

public class Dichotomy {
	public static void main(String[] args) {
		
		int[] array = Array.generateArray(10);
		array = Array.setRadomDate(array);
		Array.sort(array);
		String result = Array.search(array, 3);
		System.out.println(result);
	}
}

generate Array... 
generate Array successful... 
the Array length is: 10
the Array is:
2 6 8 1 3 4 4 1 9 5 
now we will sort it as 1~9:
now the result is: 
1 1 2 3 4 4 5 6 8 9 
3 wanted be search!
now we will search its index
It is: 3

package chapter5;

public class Dichotomy {
	public static void main(String[] args) {

		int[] array = Array.generateArray(10);
		array = new int[] { 2, 3, 3, 5, 5, 6, 7, 8, 9, 10 };
		array = Array.setSortDate(array, array);
		Array.sort(array);
		String result = Array.search(array, 4);
		System.out.println(result);
	}
}

generate Array... 
generate Array successful... 
the Array length is: 10

now we will sort it as 1~9:
now the result is: 
2 3 3 5 5 6 7 8 9 10 
4 wanted be search!
now we will search its index
Sorry, the system can't find ur Num!