[java] 이분검색

package 정렬;
import java.util.*;


public class 이분검색 {

	public static int solution(int size, int key, int[] arr) {
		int answer=0;
		Arrays.sort(arr);
		
		//이분검색
		//반으로 나눠서 
		int left=0;
		int right=size-1;
		while(left<=right) {
			int mid=(left+right)/2;
			if(arr[mid]==key) {
				answer=mid+1;
				break;
			}
			if(arr[mid]>key) {
				right=mid-1;
			}else {
				left=mid+1;
			}
		}
		
		return answer;
	}
	

	
	public static void main(String[] args) {
		이분검색 T = new 이분검색();
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int M = sc.nextInt();
		int[] arr = new int[N];
		for(int i=0; i<N;i++) {
			arr[i]=sc.nextInt();
		}
		System.out.println(solution(N,M,arr));
	
		
}}