Submission #523266

#	Time	Username	Problem	Language	Result	Execution time	Memory
523266		lucri	Combo (IOI18_combo)	C++17	100 / 100	42 ms	552 KiB

combo

#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

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);
  }
  return coins;
}*/

std::string guess_sequence(int N)
{
    std::string p;
    int val=press("AB");
    if(val>=1)
    {
        val=press("A");
        if(val==1)
            p+='A';
        else
            p+='B';
    }
    else
    {
        val=press("X");
        if(val==1)
            p+='X';
        else
            p+='Y';
    }
    if(N==1)
        return p;
    for(int l=1;l+2<=N;++l)
    {
        if(p[0]=='A')
        {
            val=press(p+'B'+p+"XB"+p+"XX"+p+"XY");
            if(val-l==0)
                p+='Y';
            if(val-l==1)
                p+='B';
            if(val-l==2)
                p+='X';
        }
        else if(p[0]=='B')
        {
            val=press(p+'A'+p+"XA"+p+"XX"+p+"XY");
            if(val-l==0)
                p+='Y';
            if(val-l==1)
                p+='A';
            if(val-l==2)
                p+='X';
        }
        else if(p[0]=='X')
        {
            val=press(p+'A'+p+"BA"+p+"BB"+p+"BY");
            if(val-l==0)
                p+='Y';
            if(val-l==1)
                p+='A';
            if(val-l==2)
                p+='B';
        }
        else if(p[0]=='Y')
        {
            val=press(p+'A'+p+"XA"+p+"XX"+p+"XB");
            if(val-l==0)
                p+='B';
            if(val-l==1)
                p+='A';
            if(val-l==2)
                p+='X';
        }
    }
    if(press(p+'A'+p+'B')==N)
    {
        if(press(p+'A')==N)
            p+='A';
        else
            p+='B';
    }
    else
    {
        if(press(p+'X')==N)
            p+='X';
        else
            p+='Y';
    }
    return p;
}

/*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);
  if (answer != S) {
    wrong_answer("wrong guess");
    exit(0);
  }
  printf("Accepted: %d\n", num_moves);
  return 0;
}*/

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