Submission #542098

#	Time	Username	Problem	Language	Result	Execution time	Memory
542098		Mdominykas	Miners (IOI07_miners)	C++14	84 / 100	1600 ms	468 KiB

miners

/*input
16
MMBMBBBBMMMMMBMB
*/
/*input
6
MBMFFB
*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <unistd.h>
using namespace std;
using namespace __gnu_pbds;

#define ws(x) cerr << #x << " is " << x << endl

typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> orderedTree;
typedef long long ll;

#define mp make_pair

int encode(vector<int> &food)
{
	if(food.size() == 0)
		return 0;
	else if (food.size() == 1)
		return food.back();
	else if (food.size() >= 2)
		return 3 * food[food.size() - 2] + food[food.size() - 1];
}

// int encode(vector<int> &food)
// {
// 	cout << "encodinu:" << endl;
// 	for(int i : food)
// 		cout << i << " ";
// 	cout << endl;
// 	cout << encode1(food) << endl;
// 	return encode1(food);
// }

pair<int, int> addFood(int val, int newVal)
{
	// cout << "val = " << val << endl;
	// cout << "newVal = " << newVal << endl;
	vector<int> oldFood;
	if((val < 4) && (val > 0))
		oldFood.push_back(val);
	else if (val >= 4)
	{
		oldFood.push_back((val - 1) / 3);
		if(val %3 == 0)
			oldFood.push_back(3);
		else
			oldFood.push_back(val % 3);
	}
	// cout << "food = " << endl;
	// for(int f : oldFood)
		// cout << f << " ";
	// cout << endl;
	// reverse(oldFood.begin(), oldFood.end());
	oldFood.push_back(newVal);

	int count[4] = {};
	for(int f : oldFood)
	{
		count[f]++;
	}

	int coal = 0;
	for(int i = 1; i < 4; i++)
	{
		if(count[i] > 0)
			coal++;
	}
	// assert(encode(oldFood) < 13);
	return make_pair(encode(oldFood), coal);
}


int main()
{
	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

	int N;
	cin >> N;
	string food;
	cin >> food;

	const int numOps = 13;
	int states[2][numOps][numOps];

	const int MININF = - 5 * N - (1e6);
	for(int x = 0; x < numOps; x++)
	{
		for(int y = 0; y < numOps; y++)
		{
			states[0][x][y] = MININF;
			states[0][x][y] = MININF;
		}
	}

	states[0][0][0] = 0;


	for(int i = 0; i < N; i++)
	{
		int num;
		if(food[i] == 'M')
			num = 1;
		else if (food[i] == 'B')
			num = 2;
		else if (food[i] == 'F')
			num = 3;

		// cout << "num = " << num << endl;

		int curId = i % 2, nextId = (i + 1) % 2;
		for(int x = 0; x < numOps; x++)
		{
			for(int y = 0; y < numOps; y++)
				states[nextId][x][y] = MININF;
		}

		for(int x = 0; x < numOps; x++)
		{
			for(int y = 0; y < numOps; y++)
			{
				pair<int, int> next1 = addFood(x, num);
				states[nextId][next1.first][y] = max(states[nextId][next1.first][y], states[curId][x][y] + next1.second);
				pair<int, int> next2 = addFood(y, num);
				states[nextId][x][next2.first] = max(states[nextId][x][next2.first], states[curId][x][y] + next2.second);
			}
		}
	}

	int ans = 0;
	for(int x = 0; x < numOps; x++)
	{
		for(int y = 0; y < numOps; y++)
			ans = max(ans, states[N%2][x][y]);
	}

	cout << ans;



	return 0;
}

Compilation message (stderr)

miners.cpp: In function 'int encode(std::vector<int>&)':
miners.cpp:31:1: warning: control reaches end of non-void function [-Wreturn-type]
   31 | }
      | ^
miners.cpp: In function 'int main()':
miners.cpp:132:42: warning: 'num' may be used uninitialized in this function [-Wmaybe-uninitialized]
  132 |     pair<int, int> next2 = addFood(y, num);
      |                                          ^

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 7 / 7
• Subtask 7: 8 / 8
• Subtask 8: 8 / 8
• Subtask 9: 8 / 8
• Subtask 10: 8 / 8
• Subtask 11: 0 / 8
• Subtask 12: 0 / 8