[백준 2579: 계단 오르기] - C++

www.acmicpc.net/problem/2579

2579번: 계단 오르기

#include<iostream>
#include<math.h>
#include<algorithm>
using namespace std;
#define MAX 301
int DP[MAX];
int stair[MAX];
int main() 
{	
	int n = 0;;
	cin >> n;
	for (int i = 0; i < n; i++) cin >> stair[i];

	DP[0] = stair[0];
	DP[1] = max(stair[1], stair[0] + stair[1]);
	DP[2] = max(stair[0] + stair[2], stair[1] + stair[2]);

	for (int i = 3; i < n; i++)
	{
		DP[i] = max(stair[i] + DP[i - 2],
				     stair[i] + stair[i - 1] + DP[i - 3]);
	}

	//result
	cout << DP[n - 1];
	return 0;
}//end of main