Submission #209348

#	Time	Username	Problem	Language	Result	Execution time	Memory
209348		mode149256	Paint By Numbers (IOI16_paint)	C++14	100 / 100	1358 ms	99372 KiB

paint

/*input

*/
#include <bits/stdc++.h>
#include "paint.h"

using namespace std;

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef pair<ld, ld> pd;

typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<vl> vll;
typedef vector<pi> vpi;
typedef vector<vpi> vpii;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
typedef vector<pd> vpd;
typedef vector<bool> vb;
typedef vector<vb> vbb;
typedef std::string str;
typedef std::vector<str> vs;

#define x first
#define y second
#define debug(...) cout<<"["<<#__VA_ARGS__<<": "<<__VA_ARGS__<<"]\n"

const int MOD = 1000000007;
const ll INF = std::numeric_limits<ll>::max();
const int MX = 100101;
const ld PI = 3.14159265358979323846264338327950288419716939937510582097494L;

template<typename T>
pair<T, T> operator+(const pair<T, T> &a, const pair<T, T> &b) { return pair<T, T>(a.x + b.x, a.y + b.y); }
template<typename T>
pair<T, T> operator-(const pair<T, T> &a, const pair<T, T> &b) { return pair<T, T>(a.x - b.x, a.y - b.y); }
template<typename T>
T operator*(const pair<T, T> &a, const pair<T, T> &b) { return (a.x * b.x + a.y * b.y); }
template<typename T>
T operator^(const pair<T, T> &a, const pair<T, T> &b) { return (a.x * b.y - a.y * b.x); }

template<typename T>
void print(vector<T> vec, string name = "") {
	cout << name;
	for (auto u : vec)
		cout << u << ' ';
	cout << '\n';
}


str solve_puzzle(str s, vi c) {
	int N = (int)s.size();
	int K = (int)c.size();

	s.insert(s.begin(), ' ');
	c.insert(c.begin(), 0);

	vbb dp(N + 1, vb(K + 1, false));
	vii trues(K + 1);
	vi black(N + 1, 0);
	vi white(N + 1, 0);

	for (int i = 1; i <= N; ++i)
	{
		black[i] = black[i - 1] + int(s[i] == 'X');
		white[i] = white[i - 1] + int(s[i] == '_');
	}

	vi lastB(N + 1);
	vi lastW(N + 1);

	{
		int lb = -1;
		int lw = -1;
		for (int i = 0; i <= N; ++i)
		{
			if (s[i] == 'X') lb = i;
			if (s[i] == '_') lw = i;

			lastB[i] = lb;
			lastW[i] = lw;
		}
	}

	auto get = [](int a, int b, vi & vec) {
		return vec[b] - (a ? vec[a - 1] : 0);
	};

	dp[0][0] = true;
	trues[0].emplace_back(-1);

	// print(white);
	// print(black);
	for (int k = 1; k <= K; ++k)
	{
		for (int n = 1; n <= N; ++n)
		{
			if (s[n] == '_') continue;
			if (n - c[k] < 0) continue;
			if (get(n - c[k] + 1, n, white) > 0) continue;
			if (k == K and get(n + 1, N, black) > 0) continue;
			
			int lb = lastB[n - c[k]];

			auto it = lower_bound(trues[k - 1].begin(), trues[k - 1].end(), lb);
			// printf("k = %d, n = %d whites = %d\n", k, n, get(n - c[k], n, white));
			// printf("lb = %d, it = %d\n", lb, *it);
			if (it != trues[k - 1].end() and * it < n - c[k]) {
				dp[n][k] = true;
				trues[k].emplace_back(n);
			}
		}
	}

	// for (int i = 1; i <= K; ++i) print(trues[i]);

	vi yrB(N + 2, 0);
	vi yrW(N + 2, 0);

	{
		vb legal(N + 1, true);

		for (int k = K; k >= 1; --k)
		{
			vi newLegal(N + 2, 0);

			for (int n = 1; n <= N; ++n)
			{
				if (dp[n][k] and legal[n]) {
					yrB[n - c[k] + 1]++;
					yrB[n + 1]--;

					int lb = lastB[n - c[k]];

					auto it = lower_bound(trues[k - 1].begin(), trues[k - 1].end(), lb);
					// printf("k = %d, n = %d whites = %d\n", k, n, get(n - c[k], n, white));
					// printf("lb = %d, it = %d\n", lb, *it);
					if (it != trues[k - 1].end() and * it < n - c[k]) {

						yrW[*it + 1]++;
						yrW[n - c[k] + 1]--;

						newLegal[max(1, *it)]++;
						newLegal[n - c[k]]--;
					}
				}
			}
			for (int i = 1; i <= N; ++i)
			{
				newLegal[i] += newLegal[i - 1];
				legal[i] = bool(newLegal[i] > 0);
			}
		}
	}
	int pab = trues[K][0];

	yrW[pab + 1]++;

	// printf("pab = %d\n", pab);
	str ats(N, '?');


	for (int i = 1; i <= N; ++i)
	{
		yrW[i] += yrW[i - 1];
		yrB[i] += yrB[i - 1];

		if (s[i] != '.') {
			ats[i - 1] = s[i];
			continue;
		}

		if (yrB[i] > 0 and yrW[i] > 0) ats[i - 1] = '?';
		else if (yrW[i] > 0) ats[i - 1] = '_';
		else if (yrB[i] > 0) ats[i - 1] = 'X';
	}
	// print(yrW, "yrW: ");
	// print(yrB, "yrB: ");

	return ats;
}

• Subtask 1: 7 / 7
• Subtask 2: 3 / 3
• Subtask 3: 22 / 22
• Subtask 4: 27 / 27
• Subtask 5: 21 / 21
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10