Submission #68502

#	Time	Username	Problem	Language	Result	Execution time	Memory
68502		aome	parentrises (BOI18_parentrises)	C++17	100 / 100	214 ms	116708 KiB

parentrises

#include <bits/stdc++.h>

using namespace std;

namespace Task1 {
	char color[1000005];

	void solve() {
		int q; cin >> q;
		while (q--) {
			string s; cin >> s;
			stack<int> st;
			stack<int> st2;
			stack<int> st3;
			bool fail = 0;
			for (int i = 0; i < s.size(); ++i) {
				if (s[i] == '(') st.push(i), color[i] = 'G';
				else {
					if (st.size()) {
						st2.push(i), color[i] = 'G', st3.push(st.top()), st.pop();
					}
					else {
						if (!st2.size()) { fail = 1; break; }
						color[i] = 'R', color[st2.top()] = 'B', st2.pop(), st3.pop();
					}
				}
			}
			while (st.size() && st3.size()) {
				color[st.top()] = 'R', color[st3.top()] = 'B';
				st.pop(), st3.pop();
			}
			while (st.size()) st.pop();
			while (st2.size()) st2.pop();
			for (int i = 0; i < s.size(); ++i) {
				if (s[i] == '(') {
					if (color[i] == 'G' || color[i] == 'R') st.push(i);
					if (color[i] == 'G' || color[i] == 'B') st2.push(i);
				}
				else {
					if (color[i] == 'G' || color[i] == 'R') {
						if (!st.size()) { fail = 1; break; }
						st.pop();
					}
					if (color[i] == 'G' || color[i] == 'B') {
						if (!st2.size()) { fail = 1; break; }
						st2.pop();
					}
				}
			}
			if (st.size() || st2.size()) fail = 1;
			if (fail) cout << "impossible\n";
			else {
				for (int i = 0; i < s.size(); ++i) cout << color[i]; cout << '\n';
			}
		}
	}
}

namespace Task2 {
	const int N = 305;
	const int mod = 1e9 + 7;

	int f[N][N][N][2], g[N][2], h[N];

	void add(int &x, int y) { x += x + y >= mod ? y - mod : y; }

	void solve() {
		f[0][0][0][0] = 1;
		for (int i = 0; i <= 300; ++i) {
			for (int j = 0; j <= i; ++j) {
				for (int k = 0; k <= i; ++k) {
					for (int l = 0; l <= 1; ++l) {
						add(f[i + 1][j + 1][k][l], f[i][j][k][l]);
						if (j) add(f[i + 1][j - 1][k + 1][1], f[i][j][k][l]);
						else if (k) add(f[i + 1][j][k - 1][0], f[i][j][k][l]);
					}
				}
			}
			for (int j = 0; j <= i; ++j) {
				add(g[i][0], f[i][0][j][0]);
				add(g[i][1], f[i][0][j][1]);
			}
		}
		for (int i = 1; i <= 300; ++i) {
			for (int j = 0; j <= i; ++j) {
				add(h[i], 1LL * (g[j][0] + g[j][1]) * g[i - j][0] % mod);
			}
		}
		int q; cin >> q;
		while (q--) {
			int x; cin >> x, cout << h[x] << '\n';
		}
	}
}

int main() {
	ios::sync_with_stdio(false);
	int P; cin >> P;
	if (P == 1) Task1::solve();
	else Task2::solve();
}

Compilation message (stderr)

parentrises.cpp: In function 'void Task1::solve()':
parentrises.cpp:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < s.size(); ++i) {
                    ~~^~~~~~~~~~
parentrises.cpp:34:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < s.size(); ++i) {
                    ~~^~~~~~~~~~
parentrises.cpp:53:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); ++i) cout << color[i]; cout << '\n';
                     ~~^~~~~~~~~~
parentrises.cpp:53:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for (int i = 0; i < s.size(); ++i) cout << color[i]; cout << '\n';
     ^~~
parentrises.cpp:53:58: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
     for (int i = 0; i < s.size(); ++i) cout << color[i]; cout << '\n';
                                                          ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 11 / 11
• Subtask 3: 6 / 6
• Subtask 4: 28 / 28
• Subtask 5: 6 / 6
• Subtask 6: 16 / 16
• Subtask 7: 28 / 28