Submission #143151

#	Time	Username	Problem	Language	Result	Execution time	Memory
143151		neki	Combo (IOI18_combo)	C++14	91 / 100	51 ms	588 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
#define loop(i, a, b) for(int i=a;i<b;i++)
using namespace std;
vector<string>zn={"A", "B", "X", "Y"};
 
std::string guess_sequence(int N) {
    int st;
    vector<int> ost;
    loop(i, 0, 4){
        if(press(zn[i])){
          st=i;
          loop(j, 0, 4) if(j!=i) ost.push_back(j);
          break;
          }
    }
    string ans=zn[st];
    if(N==1) return ans;
    loop(i, 1, N-1){
        string ask=ans+zn[ost[0]]+ans+zn[ost[1]]+zn[ost[0]]+ans+zn[ost[1]]+zn[ost[1]]+ans+zn[ost[1]]+zn[ost[2]];
        int res=press(ask);
        if(res==ans.length()) ans+=zn[ost[2]];
        else if(res==ans.length()+1) ans+=zn[ost[0]];
        else ans+=zn[ost[1]];
    }
    loop(i, 0, 3){
        if(press(ans+zn[ost[i]])==ans.length()+1) return ans+zn[ost[i]];
    }
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:22:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         if(res==ans.length()) ans+=zn[ost[2]];
      |            ~~~^~~~~~~~~~~~~~
combo.cpp:23:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |         else if(res==ans.length()+1) ans+=zn[ost[0]];
      |                 ~~~^~~~~~~~~~~~~~~~
combo.cpp:27:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |         if(press(ans+zn[ost[i]])==ans.length()+1) return ans+zn[ost[i]];
      |            ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
combo.cpp:9:17: warning: control reaches end of non-void function [-Wreturn-type]
    9 |     vector<int> ost;
      |                 ^~~
combo.cpp:17:21: warning: 'st' may be used uninitialized in this function [-Wmaybe-uninitialized]
   17 |     string ans=zn[st];
      |                     ^

• Subtask 1: 5 / 5
• Subtask 2: 86 / 95