[백준] 2579 계단 오르기 [자바]

 

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https://st-lab.tistory.com/132

[백준] 2579번 : 계단 오르기 - JAVA [자바]

 

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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;

public class Main {
	static int[] arr;
	static int[] stair = null;
	public static void main(String arg[]) throws IOException {
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    	int N = Integer.parseInt(br.readLine());
    	stair = new int[N+1];
    	arr = new int[N+1];
    	for(int i = 1; i <= N; i++)
    		arr[i] = Integer.parseInt(br.readLine());
    	stair[1] = arr[0];
    	stair[0] = 0;
    	dp(N);
    	System.out.println(stair[N]);
    }
	static int dp(int n) {
		if(n <= 0)
			return 0;
		if(stair[n] == 0) {
			stair[n] = Math.max(dp(n-2), dp(n-3)+arr[n-1]) + arr[n];
			return stair[n];
		}
		else
			return stair[n];
	}
}