[백준]_1654_랜선자르기

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class B1654 {
	static int N, M, cnt = 0;
	static long[] arr;

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		N = Integer.parseInt(st.nextToken());
		M = Integer.parseInt(st.nextToken());
		long max = 0;
		arr = new long[N];
		for (int i = 0; i < N; i++) {
			arr[i] = Integer.parseInt(br.readLine());
			max = Math.max(arr[i], max);
		}
		binarySearch(1,max);
	}
	
	private static void binarySearch(long start, long end) {
        long mid = 0;
        while (start <= end) {
        	int cnt = 0;
        	
            mid = (start + end) / 2;

			// 개수를 찾는 과정
            for(int i =0;i<N;i++) {
            	cnt+=arr[i]/mid;
            }
            if (cnt < M) {
                end = mid - 1;
            } else {
                start = mid + 1;
            }
			// 최대 길이를 구하므로 여기서 부등호
        }
        System.out.println(start-1);
    }
}