Submission #206673

#	Time	Username	Problem	Language	Result	Execution time	Memory
206673		opukittpceno_hhr	Rope (JOI17_rope)	C++17	0 / 100	2579 ms	376 KiB

rope

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

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

int cans(vector<int> s) {
	int n = (int)s.size();
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= N; j++) {
			dp[i][j] = -1;
		}
	}
	function<int(int, 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) & (!eq(s[i], s[i + len - 1]));
		}
		return dp[i][len];
	};
	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(s.begin(), s.end());
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= N; j++) {
			dp[i][j] = -1;
		}
	}
	for (int i = 0; i < n; i++) {
		for (int len = 2; i + len <= n; len++) {
			sdp[i + len / 2] |= (sdp[i] & can(i, len));
		}
	}
	int ans = n;
	for (int i = 0; i <= n; i++) {
		if (n - 2 - i >= 0) {
			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);
		}
	}
	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';
	}
}

Compilation message (stderr)

rope.cpp: In function 'int cans(std::vector<int>)':
rope.cpp:63:6: warning: array subscript is above array bounds [-Warray-bounds]
  fill(pdp, pdp + N + 1, 0);
  ~~~~^~~~~~~~~~~~~~~~~~~~~
rope.cpp:64:6: warning: array subscript is above array bounds [-Warray-bounds]
  fill(sdp, sdp + N + 1, 0);
  ~~~~^~~~~~~~~~~~~~~~~~~~~
cc1plus: warning: 'void* __builtin_memset(void*, int, long unsigned int)' writing 60 bytes into a region of size 56 overflows the destination [-Wstringop-overflow=]
cc1plus: warning: 'void* __builtin_memset(void*, int, long unsigned int)' writing 60 bytes into a region of size 56 overflows the destination [-Wstringop-overflow=]

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