[백준] 1932 - 연속합 [JAVA]

 

코드 (Top-down)

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

public class Main {

    static int[] arr;
    static int[] dp;
    static int max;

    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int N = Integer.parseInt(br.readLine());
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");

        arr = new int[N];
        dp = new int[N];

        for (int i = 0; i < N; i++) {
            arr[i] = Integer.parseInt(st.nextToken());
        }

        dp[0] = arr[0];
        max = dp[0];
        
        // Top-down
        solution(N - 1);
        System.out.println(max);
    }


    static int solution(int n) {
        if (n == 0) {
            return dp[0];
        }

        dp[n] = Math.max(solution(n - 1) + arr[n], arr[n]);

        if (dp[n] > max) {
            max = dp[n];
        }

        return dp[n];
    }
}

 

코드(Bottom-up)

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

public class Main {

    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int N = Integer.parseInt(br.readLine());

        int[] arr = new int[N];
        int[] dp = new int[N];

        StringTokenizer st = new StringTokenizer(br.readLine());

        for (int i = 0; i < N; i++) {
            int num = Integer.parseInt(st.nextToken());
            arr[i] = num;
        }

        dp[0] = arr[0];
        int max = arr[0];

        for (int i = 1; i < arr.length; i++) {

            dp[i] = Math.max(dp[i - 1] + arr[i], arr[i]);

            max = Math.max(max, dp[i]);
        }
        System.out.println(max);
    }

}