Submission #206685

#	Time	Username	Problem	Language	Result	Execution time	Memory
206685		opukittpceno_hhr	Rope (JOI17_rope)	C++17	0 / 100	1303 ms	504 KiB

rope

#ifndef LOCAL
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#endif

#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>
#include <functional>

using namespace std;

const int N = 15;

int dp[N][N + 1];
int sdp[N + 1];
int pdp[N + 1];

int ts[N];
int s[N + 1];

int can(int i, int len) {
	if (len % 2 == 1) {
		return 0;
	}
	if (len == 0) {
		return 1;
	}
	if (dp[i][len] == -1) {
		dp[i][len] = can(i + 1, len - 2) & ((ts[i] == ts[i + len - 1]));
	}
	return dp[i][len];
}

void ref() {
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= N; j++) {
			dp[i][j] = -1;
		}
	}
}

int cans(int n) {
	ref();
	fill(pdp, pdp + N + 1, 0);
	fill(sdp, sdp + N + 1, 0);
	pdp[0] = 1;
	sdp[0] = 1;
	for (int i = 0; i < n; i++) {
		for (int len = 2; i + len <= n; len++) {
			pdp[i + len / 2] |= (pdp[i] & can(i, len));
		}
	}
	reverse(ts, ts + n);
	ref();
	for (int i = 0; i < n; i++) {
		for (int len = 2; i + len <= n; len++) {
			sdp[i + len / 2] |= (sdp[i] & can(i, len));
		}
	}
	for (int i = 0; i <= n && n - 2 - i >= 0; i++) {
		if (pdp[i] & sdp[n - 2 - i]) {
			// cout << "NO\n";
			// for (int i = 0; i < n; i++) {
			// 	cout << ts[i] << ' ';
			// }
			// cout << endl;
			return 1;
		}
	}
	// cout << "NO\n";
	// for (int i = 0; i < n; i++) {
	// 	cout << ts[i] << ' ';
	// }
	// cout << endl;
	return 0;
}

int solve(int n, int a, int b) {
	int ans = n;
	for (int i = 0; i < (1 << n); i++) {
		for (int j = 0; j < n; j++) {
			if ((i >> j) & 1) {
				ts[j] = a;
			} else {
				ts[j] = b;
			}
		}
		if (cans(n)) {
			int c = 0;
			for (int j = 0; j < n; j++) {
				c += (s[j] != ts[j]);
			}
			ans = min(ans, c);
		}
	}
	return ans;
}

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

	int n, m;
	cin >> n >> m;
	for (int i = 0; i < n; i++) {
		cin >> s[i];
		s[i]--;
	}
	vector<int> ans(m, n);
	for (int i = 0; i < m; i++) {
		for (int j = i + 1; j < m; j++) {
			int v = solve(n, 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