Submission #388359

#	Time	Username	Problem	Language	Result	Execution time	Memory
388359		warner1129	Combo (IOI18_combo)	C++17	5 / 100	1 ms	200 KiB

combo

// #define local

#include <bits/stdc++.h>
using namespace std;

#ifdef local
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <string>
// #include "combo.h"

namespace {

constexpr int MAX_N = 2000;
constexpr int MAX_NUM_MOVES = 8000;

int N;
std::string S;

int num_moves;

void wrong_answer(const char *MSG) {
  printf("Wrong Answer: %s\n", MSG);
  exit(0);
}

}  // namespace

string guess_sequence(int);

int press(std::string p) {
  if (++num_moves > MAX_NUM_MOVES) {
    wrong_answer("too many moves");
  }
  int len = p.length();
  if (len > 4 * N) {
    wrong_answer("invalid press");
  }
  for (int i = 0; i < len; ++i) {
    if (p[i] != 'A' && p[i] != 'B' && p[i] != 'X' && p[i] != 'Y') {
      wrong_answer("invalid press");
    }
  }
  int coins = 0;
  for (int i = 0, j = 0; i < len; ++i) {
    if (j < N && S[j] == p[i]) {
      ++j;
    } else if (S[0] == p[i]) {
      j = 1;
    } else {
      j = 0;
    }
    coins = std::max(coins, j);
  }
  cout << "p = " << p << " ret = " << coins << '\n';
  return coins;
}

int main() {
  char buffer[MAX_N + 1];
  if (scanf("%s", buffer) != 1) {
    fprintf(stderr, "Error while reading input\n");
    exit(1);
  }
  S = buffer;
  N = S.length();

  num_moves = 0;
  std::string answer = guess_sequence(N);
  cout << "ans = " << answer << '\n';
  if (answer != S) {
    wrong_answer("wrong guess");
    exit(0);
  }
  printf("Accepted: %d\n", num_moves);
  return 0;
}
#else
#include <combo.h>
#endif

string guess_sequence(int n) {
	string ans, tmp;
	int ret, len = 1;
	ret = press("AB");
	if (ret >= 1) {
		ret = press("A");
		if (ret == 1) ans = "A";
		else ans = "B";
	}	
	else {
		ret = press("X");
		if (ret == 1) ans = "X";
		else ans = "Y";
	}
	vector<string> L;
	if ("A" != ans) L.push_back("A");
	if ("B" != ans) L.push_back("B");
	if ("X" != ans) L.push_back("X");
	if ("Y" != ans) L.push_back("Y");
	string P[4];
	P[0] = L[0] + L[0], P[1] = L[0] + L[1], P[2] = L[0] + L[2];
	P[3] = L[1];
	for (int i = 2; i < n; i++) {
		tmp = "";
		for (int j = 0; j < 4; j++)
			tmp += (ans + P[j]);
		ret = press(tmp);
		if (ret == len + 2) ans += L[0];
		else if (ret == len + 1) ans += L[1];
		else if (ret == len) ans += L[2];
		len++;
	}
	ret = press(ans + L[0] + ans + L[1]);
	if (ret == len+1) {
		ret = press(ans + L[0]);
		if (ret == len+1) ans += L[0];
		else ans += L[1];
	}
	else if (ret == len)
		ans += L[2];
	return ans;	
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95