2579 계단오르기

#include <stdio.h>
#include <algorithm>
 
using namespace std;
 
int stair[305] = { 0 };
int dp[305] = { 0 };
 
int main() {
    int n;
    scanf("%d", &n);
 
    for (int i = 1; i <= n; i++) {
        scanf("%d", &stair[i]);
    }
 
    dp[1] = stair[1];
    dp[2] = stair[1] + stair[2];
    for (int i = 3; i <= n; i++) {
        dp[i] = stair[i] + max(dp[i - 3] + stair[i - 1], dp[i - 2]);
    }
    printf("%d", dp[n]);
}