BOJ 11052번 카드 구매하기

package BOJ;

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

public class CardBuy_11052 {

    private static int[] arr;
    private static int[] prices;


    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n =  Integer.parseInt(br.readLine());
        prices = Arrays.asList(br.readLine().split("\\s")).stream().mapToInt(Integer::parseInt).toArray();
        // D(n) : n개의 카드를 사는데 지불하는 최대 금액
        // D(n-i) + P[i]
        arr = new int[n+1];
        solve(n);
        System.out.println(arr[n]);
    }

    private static void solve(int n) {
        for(int i=1; i<=n; i++){
            for(int j=1; j<=i; j++){
                if(arr[i] < arr[i-j] + prices[j-1])
                    arr[i] = arr[i-j] + prices[j-1];
            }
        }
    }
}