[2579] 계단 오르기

#include <iostream>
#define MAX 301
using namespace std;
int max(int a, int b);
int main()
{
	int testcase, i;
	int dp[MAX], arr[MAX];
	cin >> testcase;
	for (i = 0; i < testcase; i++)
		cin >> arr[i];
	dp[0] = arr[0];
	dp[1] = max(arr[0] + arr[1], arr[1]);
	dp[2] = max(arr[0], arr[1]) + arr[2];
	for (i = 3; i < testcase; i++)
		dp[i] = max(dp[i-2] + arr[i], dp[i-3]+arr[i-1] + arr[i]);
	cout << dp[testcase-1] << endl;
	return 0;
}
int max(int a, int b)
{
	return (a > b) ? a : b;
}