[백준 2579] 계단 오르기 (C++/Java)

- C++

#include<cstdio>
#include<algorithm>
int a[301],dp[301];
using namespace std;
int main(void)
{
    int x;
    scanf("%d", &x);
 
    for (int i=1; i<=x; i++) scanf("%d", &a[i]);
    
    dp[0]=0;
    dp[1]=a[1];
    dp[2]=a[1]+a[2];
    
    for (int i=3; i<=x; i++)
        dp[i]=max(dp[i-2]+a[i], dp[i-3]+a[i-1]+a[i]);
    
    printf("%d", dp[x]);
    return 0;
}
 

 

 

- JAVA

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));
        StringTokenizer st;
 
        int n = Integer.parseInt(br.readLine());
        int[] arr = new int[n+1];
        int[] dp = new int[n+1];
 
        for(int i=1; i<=n; i++){
            arr[i] = Integer.parseInt(br.readLine());
        }
 
        dp[1]=arr[1];
        if(n>=2) { dp[2] = Math.max(dp[1]+arr[2], arr[2]);}
        if(n>=3){
            for(int i=3; i<=n; i++){
                dp[i] = Math.max(dp[i-2]+arr[i], dp[i-3]+arr[i-1]+arr[i]);
            }
        }
 
        System.out.println(dp[n]);
    }
}