Submission #166943

#	Time	Username	Problem	Language	Result	Execution time	Memory
166943		johutha	Growing Vegetable is Fun 3 (JOI19_ho_t3)	C++17	100 / 100	294 ms	134788 KiB

joi2019_ho_t3

#include <vector>
#include <iostream>
#include <algorithm>

#define int long long

using namespace std;

struct prefsum
{
	int n;
	vector<int> vals;

	void init(vector<int> ip)
	{
		n = ip.size();
		vals.resize(n + 1);
		for (int i = 1; i <= n; i++)
		{
			vals[i] = vals[i - 1] + ip[i - 1];
		}
	}

	int operator()(int l, int r)
	{
		return vals[r] - vals[l];
	}
};

struct dpstruct
{
	prefsum veg_R;
	prefsum veg_Y;
	prefsum veg_G;

	vector<int> pos_R;
	vector<int> pos_Y;
	vector<int> pos_G;

	int R = 0, Y = 0, G = 0;

	vector<vector<vector<vector<int>>>> table;

	int dp()
	{
		for (int r = 0; r <= R; r++)
		{
			for (int y = 0; y <= Y; y++)
			{
				for (int g = 0; g <= G; g++)
				{
					for (int last = 0; last < 3; last++)
					{
						int cost = 1e15;

						if (last == 0 && r != 0)
						{
							cost = min(table[r - 1][y][g][1], table[r - 1][y][g][2]) + max(0LL, veg_Y(0, pos_R[r - 1]) - y) + max(0LL, veg_G(0, pos_R[r - 1]) - g);
						}
						else if (last == 1 && y != 0)
						{
							cost = min(table[r][y - 1][g][0], table[r][y - 1][g][2]) + max(0LL, veg_R(0, pos_Y[y - 1]) - r) + max(0LL, veg_G(0, pos_Y[y - 1]) - g);
						}
						else if (last == 2 && g != 0)
						{
							cost = min(table[r][y][g - 1][0], table[r][y][g - 1][1]) + max(0LL, veg_Y(0, pos_G[g - 1]) - y) + max(0LL, veg_R(0, pos_G[g - 1]) - r);
						}
						if (r + y + g != 0) table[r][y][g][last] = cost;
					}
				}
			}
		}

		return min(table[R][Y][G][0], min(table[R][Y][G][1], table[R][Y][G][2]));
	}

	void init(int n, string s)
	{
		vector<int> rs(n), ys(n), gs(n);
		
		
		for (int i = 0; i < n; i++)
		{
			char c = s[i];
			if (c == 'R')
			{
				R++;
				rs[i]++;
				pos_R.push_back(i);
			}
			else if (c == 'Y')
			{
				Y++;
				ys[i]++;
				pos_Y.push_back(i);
			}
			else
			{
				G++;
				gs[i]++;
				pos_G.push_back(i);
			}
		}

		veg_R.init(rs);
		veg_Y.init(ys);
		veg_G.init(gs);

		table.resize(R + 1, vector<vector<vector<int>>>(Y + 1, vector<vector<int>>(G + 1, vector<int>(3, 0))));
	}
};

signed main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int n;
	cin >> n;
	string s;
	cin >> s;
	dpstruct dps;
	dps.init(n, s);

	int res = dps.dp();

	if (res >= 1e15) cout << "-1\n";
	else cout << res << "\n";
}

• Subtask 1: 5 / 5
• Subtask 2: 55 / 55
• Subtask 3: 15 / 15
• Subtask 4: 25 / 25