Submission #544790

#	Time	Username	Problem	Language	Result	Execution time	Memory
544790		sliviu	Miners (IOI07_miners)	C++17	100 / 100	47 ms	592 KiB

miners

#pragma GCC optimize("Ofast","unroll-loops")
#include <bits/stdc++.h>

using namespace std;

int main() {
	cin.tie(0)->sync_with_stdio(0);
	int n, ans = 0, dp[2][4][4][4][4] = {}, reset[4][4][4][4], precalc[4][4][4];
	cin >> n;
	string s;
	cin >> s;
	auto cost = [&](int x, int y, int z) {
		int cnt[4] = {}, ans = 0;
		++cnt[x], ++cnt[y], ++cnt[z];
		for (int i = 1; i < 4; ++i)
			ans += !!cnt[i];
		return ans;
	};
	for (int i = 0; i < 4; ++i)
		for (int j = 0; j < 4; ++j)
			for (int k = 0; k < 4; ++k) {
				precalc[i][j][k] = cost(i, j, k);
				for (int l = 0; l < 4; ++l)
					reset[i][j][k][l] = -10000;
			}
	memcpy(dp[1], reset, sizeof(reset));
	dp[1][0][0][0][0] = 0;
	for (int i = 0; i < n; ++i) {
		int cur = s[i] == 'M' ? 1 : s[i] == 'F' ? 2 : 3;
		memcpy(dp[i & 1], reset, sizeof(reset));
		for (int fll = 0; fll < 4; ++fll)
			for (int fl = !!fll; fl < 4; ++fl)
				for (int sll = 0; sll < 4; ++sll)
					for (int sl = !!sll; sl < 4; ++sl)
						if (dp[(i & 1) ^ 1][fll][fl][sll][sl] >= 0) {
							dp[i & 1][fl][cur][sll][sl] = max(dp[i & 1][fl][cur][sll][sl], dp[(i & 1) ^ 1][fll][fl][sll][sl] + precalc[fll][fl][cur]);
							dp[i & 1][fll][fl][sl][cur] = max(dp[i & 1][fll][fl][sl][cur], dp[(i & 1) ^ 1][fll][fl][sll][sl] + precalc[sll][sl][cur]);
						}
	}
	for (int i = 0; i < 4; ++i)
		for (int j = 0; j < 4; ++j)
			for (int k = 0; k < 4; ++k)
				for (int l = 0; l < 4; ++l)
					ans = max(ans, dp[(n - 1) & 1][i][j][k][l]);
	cout << ans;
}

• 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: 8 / 8
• Subtask 12: 8 / 8