冒泡排序

package demo;

import java.util.Arrays;

import org.junit.Test;

public class Main {

	@Test
	public void testSort() {
		int[] cards = { 5, 1, 4, 6, 3, 2, 9, 8, 7, 11, 13, 10, 12 };
		sort(cards);
		System.out.println(Arrays.toString(cards));
	}

	@Test
	public void testFindKey() {

		int[] cards = { 5, 1, 4, 6, 3, 2, 9, 8, 7, 11, 13, 10, 12 };
		sort(cards);
		System.out.println(Arrays.toString(cards));
		System.out.println(findKey(cards, 5));
	}

	private void sort(int[] cards) {
		int temp;

		for (int i = 0; i < cards.length; i++) {
			for (int j = i + 1; j < cards.length; j++) {
				if (cards[i] < cards[j]) {
					temp = cards[i];
					cards[i] = cards[j];
					cards[j] = temp;
				}
			}
		}
	}

	private int findKey(int cards[], int key) {

		int indexStart = 0;
		int indexEnd = cards.length - 1;
		while (indexStart <= indexEnd) {
			int indexMid = (indexStart + indexEnd) / 2;
			if (cards[indexMid] == key) {
				return indexMid;
			} else if (cards[indexMid] > key) {
				indexStart = indexMid + 1;
			} else if(cards[indexMid] < key){
				indexEnd = indexMid - 1;
			}
		}
		return -1;
	}
}