Submission #206664

#	Time	Username	Problem	Language	Result	Execution time	Memory
206664		opukittpceno_hhr	Rope (JOI17_rope)	C++17	0 / 100	2512 ms	376 KiB

rope

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <random>

using namespace std;

const int INF = 1e9 + 239;
const int NONE = -1;

int eq(int a, int b) {
	if (a == NONE || b == NONE) {
		return 1;
	} else {
		return a == b;
	}
}

int cans(vector<int> s) {
	int n = (int)s.size();
	auto can = [&](int i, int len) {
		vector<int> a;
		assert(i + len <= n);
		for (int j = 0; j < len; j++) {
			a.push_back(s[i + j]);
		}
		int c = 0;
		for (int j = 0; j < len / 2; j++) {
			c += !eq(a[j], a[len - 1 - j]);
		}
		return c;
	};
	vector<int> pdp(n + 1, INF);
	pdp[0] = 0;
	for (int i = 0; i < n; i++) {
		for (int len = 2; i + len <= n; len++) {
			pdp[i + len / 2] = min(pdp[i + len / 2], pdp[i] + can(i, len));
		}
	}
	reverse(s.begin(), s.end());
	vector<int> sdp(n + 1, INF);
	sdp[0] = 0;
	// for (auto t : s) {
	// 	cerr << t << ' ';
	// }
	// cerr << endl;
	for (int i = 0; i < n; i++) {
		for (int len = 2; i + len <= n; len++) {
			// if (i + len / 2 == 2 && sdp[i] == 0 && can(i, len) == 0) {
			// 	cout << "? " << i << ' ' << len << endl;
			// }
			sdp[i + len / 2] = min(sdp[i + len / 2], sdp[i] + can(i, len));
		}
	}
	int ans = 0;
	for (int i = 0; i <= n; i++) {
		if (n - 2 - i >= 0) {
			// if (pdp[i] + sdp[n - 2 - i] == 0) {
			// 	cout << "! " << i << ' ' << n - 2 - i << endl;
			// }
			ans = min(ans, pdp[i] + sdp[n - 2 - i]);
		}
	}
	return ans == 0;
}

int solve(vector<int> s, int a, int b) {
	int n = (int)s.size();
	int ans = n;
	for (int i = 0; i < (1 << n); i++) {
		vector<int> ts = s;
		for (int j = 0; j < n; j++) {
			if ((i >> j) & 1) {
				ts[j] = a;
			} else {
				ts[j] = b;
			}
		}
		if (cans(ts)) {
			int c = 0;
			for (int j = 0; j < n; j++) {
				c += !eq(s[j], ts[j]);
			}
			ans = min(ans, c);
			// if (c == 0) {
			// 	cout << "hr " << endl;
			// 	for (auto t : s) {
			// 		cout << t << ' ';
			// 	}
			// 	cout << endl;
			// 	for (auto t : ts) {
			// 		cout << t << ' ';
			// 	}
			// 	cout << endl;
			// }
		}
	}
	for (auto t : s) {
		ans += (t == NONE);
	}
	return ans;
}

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

	// vector<int> a;
	// a = {2, 2, 1, 1, NONE, NONE, 2, 1, 1, 2};
	// cout << solve(a, 2, 1) << endl;

	// vector<int> a;
	// a = {2, 2, 1, 1, 1, 1, 2, 1, 1, 2};
	// cout << cans(a) << endl;

	int n, m;
	cin >> n >> m;
	vector<int> a(n);
	for (auto &t : a) {
		cin >> t;
		t--;
	}
	vector<int> ans(m, n);
	for (int i = 0; i < m; i++) {
		for (int j = i; j < m; j++) {
			vector<int> ta = a;
			for (auto &x : ta) {
				if (x != i && x != j) x = NONE;
			}
			int v = solve(ta, i, j);
			ans[i] = min(ans[i], v);
			ans[j] = min(ans[j], v);
		}
	}
	for (auto t : ans) {
		cout << t << '\n';
	}
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 30
• Subtask 3: 0 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 20