백준 2579번 C++ 풀이

#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <queue>
using namespace std;
long long buffer[400];
long long previousStair[400];
long long previousTwoStair[400];
int main() {
    cin.tie(NULL);
    ios::sync_with_stdio(false);

    long long n;
    cin >> n;
    for (long long i = 0; i < n; i++) {
        cin >> buffer[i];
    }
    previousStair[0] = buffer[0];
    if (n > 0) {
        previousTwoStair[0] = 0;
        previousStair[1] = buffer[0] + buffer[1];
        previousTwoStair[1] = buffer[1];
        if (n > 1) {
            for (long long i = 2; i < n; i++) {
                previousStair[i] = previousTwoStair[i - 1] + buffer[i];
                previousTwoStair[i] = max(previousTwoStair[i - 2], previousStair[i - 2]) + buffer[i];
            }
        }
    }
    cout << max(previousStair[n-1], previousTwoStair[n-1]);

    return 0;
}