[백준/자바] #14719

이전에 풀었던 알고리즘을 java로 옮겨 보았다. 

import java.io.*;
import java.util.*;

public class Main {

    static int H, W;
    static int[] arr;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader((System.in)));
        int answer = 0;
        StringTokenizer st = new StringTokenizer(br.readLine());
        H = Integer.parseInt(st.nextToken());
        W = Integer.parseInt(st.nextToken());
        arr = new int[W];
        String[] arrInput = br.readLine().split(" ");
        for(int i=0; i<W; i++) {
            arr[i] = Integer.parseInt(arrInput[i]);
        }
        br.close();

        int leftMax = arr[0];
        int rightMax = Arrays.stream(Arrays.copyOfRange(arr, 2, W)).max().getAsInt();
        int minMax = 0;

        for(int i=1; i<W-1; i++) {
            leftMax = Math.max(leftMax, arr[i-1]);
            rightMax = Arrays.stream(Arrays.copyOfRange(arr, i+1, W)).max().getAsInt();
            minMax = Math.min(leftMax, rightMax);
            if(minMax > arr[i]) {
                answer += (minMax - arr[i]);
            }
        }
        System.out.println(answer);
    }
}