java实现二分查找

package search;

public class BinarySearch {
	/**
	 * 二分查找
	 * 
	 * 注意：二分查找只是针对有序排列的各种数组或集合
	 * 
	 * @param target
	 * @param array
	 * @return
	 */
	static boolean binarySearch(int target, int[] array) {
		int front = 0;
		int tail = array.length - 1;
		// 判断子数组是否能再次二分
		while (front <= tail) {
			// 获取子数组的中间位置，并依据此中间位置进行二分
			int middle = (front + tail) / 2;

			if (array[middle] == target) {
				return true;
			} else if (array[middle] > target) {
				tail = middle - 1;
			} else {
				front = middle + 1;
			}
		}
		return false;
	}

	public static void main(String[] args) {
		int[] array = new int[] { 1, 2, 3, 5, 7, 9, 17, 121, 4545 };
		System.out.println(binarySearch(4545, array));
	}
}