学步园

自定义排序数组:

public class MyOrderArray {
	private int[] arr;
	private int elements;
	public MyOrderArray(){
		arr = new int[50];
	}
	/*
	 * 插入后的数组是有序的
	 */
	public void insert(int value){
		int i;
		for(i=0;i<elements;i++){
			if(arr[i]>value){
				break;
			}
		}
		for(int j=elements;j>i;j--){
			arr[j] = arr[j-1];
		}
		arr[i] = value;
		elements++;
	}
	
	/*
	 * 二分法查找
	 */
	public int binarySearch(int value){
		
		int low = 0;
		int pow = elements;
		int middle = 0;
		
		while(true){
			middle = (low+pow)/2;
			if(arr[middle] == value){
				return middle;
			}else {
				if(arr[middle]>value){
					pow = middle-1;
				}else{
					low = middle +1;
				}
			}
		}
	}
	/*
	 * 线性查找
	 */
	public int linearSearch(int value){
		int i;
		for(i=0;i<elements;i++){
			if(arr[i]==value){
				break;
			}
		}
		return i;
	}
	/*
	 * 显示数组
	 */
	public void display(){
		System.out.print("[");
		for(int i=0;i<elements;i++){
			System.out.print(arr[i]+" ");
		}
		System.out.print("]");
	}
}

测试片段:

public class TestMyOrderArray {
	public static void main(String[] args) {
		MyOrderArray myOrderArray = new MyOrderArray();
		myOrderArray.insert(23);
		myOrderArray.insert(10);
		myOrderArray.insert(4);
		myOrderArray.insert(1);
		myOrderArray.insert(56);
		myOrderArray.insert(7);
		myOrderArray.insert(100);
		myOrderArray.insert(79);
		myOrderArray.display();
		System.out.println();
		System.out.println(myOrderArray.binarySearch(56));
	}
}

输出:

[1 4 7 10 23 56 79 100 ]
5

这就是2F查找.