3020번(개똥벌레)

해결

• 

코드

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Inet4Address;
import java.util.*;

public class Main {
    static int N,H;
    static int[] ceil,floor;
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        st = new StringTokenizer(br.readLine());
        N = Integer.parseInt(st.nextToken());
        H = Integer.parseInt(st.nextToken());
        ceil= new int[H+1];
        floor = new int[H+1];

        for (int i = 0; i < N/2 ; i++) { // 길이별로 카운트
            floor[Integer.parseInt(br.readLine())]++;
            ceil[Integer.parseInt(br.readLine())]++;
        }

        // 현재 길이보다 길다면 항상 충돌하므로 뒤에서부터 누적합
        for (int i = H-1; i >0 ; i--) {
            ceil[i] += ceil[i+1];
            floor[i] += floor[i+1];
        }

        int[] stone = new int[H+1];
        int min = N+1;

        for (int i = 1; i <= H ; i++) { // 최솟값 탐색
            stone[i] = floor[i] + ceil[H-i+1];
            min = Math.min(min, stone[i]);
        }
        int cnt = 0;
        for (int i = 1; i <= H ; i++) {
            if(stone[i] == min)
                cnt++;
        }
        System.out.println(min + " " + cnt);
    }

}

참고

• 직접구현