Submission #170240

#	Time	Username	Problem	Language	Result	Execution time	Memory
170240		socho	Combo (IOI18_combo)	C++14	100 / 100	43 ms	616 KiB

combo

#include "bits/stdc++.h"
#include "combo.h"
using namespace std;

int press(string s);

string guess_sequence(int N) {
	  int xy = press("XY");
	  char first;
	  string oth;
	  if (xy > 0) {
		  // x or y
		  int x = press("X");
		  if (x > 0) {
			  first = 'X';
			  oth = "ABY";
		  }
		  else {
			  first = 'Y';
			  oth = "ABX";
		  }
	  }
	  else {
		  // a or b
		  int a = press("A");
		  if (a > 0) {
			  first = 'A';
			  oth = "BXY";
		  }
		  else {
			  first = 'B';
			  oth = "AXY";
		  }
	  }
	  string found;
	  found += first;
	  if (found.size() == N) return found;
	  for (int i=1; i<N-1; i++) {
		  // to find this i try a few things
		  int curr = i;
		  string qry = "";
		  qry += (found + oth[0]); // if my res is curr+1, then it must be oth[0] next
		  qry += (found + oth[1] + oth[0]);
		  qry += (found + oth[1] + oth[1]);
		  qry += (found + oth[1] + oth[2]); // and curr+2 means oth[1]
		  // so curr means oth[2]
		  // cout << qry << endl;
		  int res = press(qry);
		  if (res == curr) {
			  found += oth[2];
		  }
		  else if (res > curr + 1) {
			  found += oth[1];
		  }
		  else {
			  found += oth[0];
		  }
	  }
	  string oth0 = found + oth[0];
	  if (press(oth0) == N) {
		  return oth0;
	  }
	  string oth1 = found + oth[1];
	  if (press(oth1) == N) {
		  return oth1;
	  }
	  found = found + oth[2];
	  return found;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:37:21: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |    if (found.size() == N) return found;
      |        ~~~~~~~~~~~~~^~~~

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