Java实现二分查找

public class ArrayTest{
    public static void main(String[] args){
        //二分法查找：
		//前提：所要查找的数组必须有序。

        //定义数组
		int[] arr = new int[]{-98,-22,-20,1,2,3,20,29,32,100};
		//要查找的值
		int dest = -20;

		int head = 0;//初始首索引

		int end = arr.length - 1; //初始的末索引

		boolean isFlag = true;
		
		while(head <= end){
			//中间索引
			int middle = (head + end) / 2;

			if(dest == arr[middle]){
				System.out.println("找到了指定的元素位置为：" + middle);
				isFlag = false;
				break;
			}else if(arr[middle] > dest){
				end = middle - 1;
			}else{
				head = middle + 1;
			}
		}
		
		if(isFlag){
			System.out.println("很遗憾，没有找到哦");
		}
    }
}