BinarySearch

이진탐색을 재귀함수를 사용하여 구현해보았다.

import java.util.Scanner;

public class BinarySearch {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner sc = new Scanner(System.in) ;
			int[] arr= {0,1,2,3,4,5,6,7,8,9,10};
			int num=0;

			for(int i=0;i<arr.length;i++) {
				System.out.print(arr[i]+" ");
			}
			while(num>=0) {
				System.out.println("\n검색할 숫자를 입력하세요");
				num = sc.nextInt();
				System.out.println(binary(arr,0,arr.length-1,num));
			}
	}
		public static int binary(int []a,int start,  int end, int key) {
			int pc = start +((end-start)/2);
			if(start<=end) {
				if(a[pc]==key)return pc;
				else if(a[pc]>key)return binary(a,start,pc-1,key);
				else return binary(a,pc+1,end,key);
			}
			else return -1;
		}
	}