Submission #542081

#	Time	Username	Problem	Language	Result	Execution time	Memory
542081		Mdominykas	Miners (IOI07_miners)	C++14	84 / 100	1589 ms	468 KiB

miners

/*input
16
MMBMBBBBMMMMMBMB
*/
#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

vector<int> decode(int val)
{
	vector<int> ans;
	ans.push_back(val % 4);
	val /= 4;
	ans.push_back(val % 4);
	reverse(ans.begin(), ans.end());
	for(int i = 0; i < ans.size(); i++)
	{
		if(ans[i] == 0)
		{
			swap(ans[i], ans.back());
			ans.pop_back();
			i--;
		}
	}
	return ans;
}

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 4 * food[0] + food[1];
	throw "too much food";
}

int coal(vector<int> &food)
{
	int count[4] = {};
	for(int f : food)
		count[f]++;

	int ans = 0;
	for(int i = 1; i < 4; i++)
	{
		if(count[i] > 0)
			ans++;
	}
	return ans;
}

pair<int, int> addFood(int val, int newVal)
{
	vector<int> oldFood = decode(val);
	oldFood.push_back(newVal);
	int res = coal(oldFood);

	if(oldFood.size() > 2)
	{
		reverse(oldFood.begin(), oldFood.end());
		oldFood.pop_back();
		reverse(oldFood.begin(), oldFood.end());
	}
	return make_pair(encode(oldFood), res);
}


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 = 16;
	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 'std::vector<int> decode(int)':
miners.cpp:26:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |  for(int i = 0; i < ans.size(); i++)
      |                 ~~^~~~~~~~~~~~
miners.cpp: In function 'int main()':
miners.cpp:130:42: warning: 'num' may be used uninitialized in this function [-Wmaybe-uninitialized]
  130 |     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