제출 #668559

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
668559		wakaka	Flight to the Ford (BOI22_communication)	C++17	15 / 100	7032 ms	118784 KiB

communication

#include "communication.h"
#include <bits/stdc++.h>
using namespace std;
//
// --- Sample implementation for the task communication ---
//
// To compile this program with the sample grader, place:
//     communication.h communication_sample.cpp sample_grader.cpp
// in a single folder, then open the terminal in this directory (right-click onto an empty spot in the directory,
// left click on "Open in terminal") and enter e.g.:
//     g++ -std=c++17 communication_sample.cpp sample_grader.cpp
// in this folder. This will create a file a.out in the current directory which you can execute from the terminal
// as ./a.out
// See task statement or sample_grader.cpp for the input specification
//
vector<vector<array<int, 2>>> getSmallMoves() {
	const int SMALL = 100;
	const int INF = 1e9;
	vector<vector<int>> dp(SMALL, vector<int>(SMALL, INF));
	vector<vector<array<int, 2>>> move(SMALL, vector<array<int, 2>>(SMALL));
	for (int s = 0; s < SMALL; ++s)
		for (int a = 0; a <= s; ++a) {
			int b = s - a;
			if (s <= 2) {
				dp[a][b] = 0;
				continue;
			}
			for (int a0 = 0; a0 <= a; ++a0)
				for (int b0 = 0; b0 <= b; ++b0) {
					if (a != a0 && b != b0) assert(dp[a0][b0] <= dp[a][b]);
					// Note we ignore a' + b' == a + b and a' >= a to prevent cycles,
					// but that's OK since it is not needed to consider those. (no proof, so dp[a][b] may not be optimal)
					int v = max(dp[a0 + b0][a - a0], dp[s - a0 - b0][a0]) + 1;
					if (v < dp[a][b]) {
						dp[a][b] = v;
						move[a][b] = {a0, b0};
					}
				}
			assert(dp[a][b] < INF);
		}
	return move;
}

void encode(int N, int X) {
	auto move = getSmallMoves();
	vector<int> lastTrue, lastFalse;
	for (int i = 1; i <= N; ++i) lastTrue.push_back(i);
	while (lastTrue.size() + lastFalse.size() > 2) {
		int a = lastTrue.size(), b = lastFalse.size();
		int a0 = a / 2, b0 = b / 2;
		if (a + b < move.size()) {
			a0 = move[a][b][0];
			b0 = move[a][b][1];
		}
		vector<int> S;
		S.insert(S.end(), lastTrue.begin(), lastTrue.begin() + a0);
		S.insert(S.end(), lastFalse.begin(), lastFalse.begin() + b0);
		int bit = find(S.begin(), S.end(), X) != S.end();
		int bitSent = send(bit);
		if (bitSent == 1) {
			lastFalse = vector<int>(lastTrue.begin() + a0, lastTrue.end());
			lastTrue = S;
		} else {
			vector<int> T;
			T.insert(T.end(), lastTrue.begin() + a0, lastTrue.end());
			T.insert(T.end(), lastFalse.begin() + b0, lastFalse.end());
			lastFalse = vector<int>(lastTrue.begin(), lastTrue.begin() + a0);
			lastTrue = T;
		}
	}
}

pair<int, int> decode(int N) {
	auto move = getSmallMoves();
	vector<int> lastTrue, lastFalse;
	for (int i = 1; i <= N; ++i) lastTrue.push_back(i);
	while (lastTrue.size() + lastFalse.size() > 2) {
		int a = lastTrue.size(), b = lastFalse.size();
		int a0 = a / 2, b0 = b / 2;
		if (a + b < move.size()) {
			a0 = move[a][b][0];
			b0 = move[a][b][1];
		}
		vector<int> S;
		S.insert(S.end(), lastTrue.begin(), lastTrue.begin() + a0);
		S.insert(S.end(), lastFalse.begin(), lastFalse.begin() + b0);
		int bit = receive();
		if (bit == 1) {
			lastFalse = vector<int>(lastTrue.begin() + a0, lastTrue.end());
			lastTrue = S;
		} else {
			vector<int> T;
			T.insert(T.end(), lastTrue.begin() + a0, lastTrue.end());
			T.insert(T.end(), lastFalse.begin() + b0, lastFalse.end());
			lastFalse = vector<int>(lastTrue.begin(), lastTrue.begin() + a0);
			lastTrue = T;
		}
	}
	vector<int> S = lastTrue;
	S.insert(S.end(), lastFalse.begin(), lastFalse.end());
	assert(S.size() <= 2);
	if (S.size() == 1) S.push_back(S[0]);
	return {S[0], S[1]};
}

컴파일 시 표준 에러 (stderr) 메시지

communication.cpp: In function 'void encode(int, int)':
communication.cpp:51:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::array<int, 2> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |   if (a + b < move.size()) {
      |       ~~~~~~^~~~~~~~~~~~~
communication.cpp: In function 'std::pair<int, int> decode(int)':
communication.cpp:80:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::array<int, 2> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |   if (a + b < move.size()) {
      |       ~~~~~~^~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 0 / 85