Submission #939817

#	Time	Username	Problem	Language	Result	Execution time	Memory
939817		snpmrnhlol	Combo (IOI18_combo)	C++17	100 / 100	29 ms	1864 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
char v[4] = {'A','X','Y','B'};
string guess_sequence(int n){
    string s = "";
    string ans = "";
    for(int i = 0;i < 2*n;i++)s+="A";
    for(int i = 0;i < 2*n;i++)s+="X";
    int a = press(s);
    s.clear();
    for(int i = 0;i < 2*n;i++)s+="A";
    for(int i = 0;i < 2*n;i++)s+="Y";
    int b = press(s);
    if(a && b)ans+="A";
    if(!a && b)ans+="Y";
    if(a && !b)ans+="X";
    if(!a && !b)ans+="B";
    if(n == 1)return ans;
    char c1,c2,c3;
    for(int i = 0;i < 4;i++){
        if(v[i] != ans[0]){
            c1 = c2;
            c2 = c3;
            c3 = v[i];
        }
    }
    for(int i = 0;i < n - 2;i++){
        string g = "";
        g+=ans;g+=c2;
        g+=ans;g+=c3;g+=c1;
        g+=ans;g+=c3;g+=c2;
        g+=ans;g+=c3;g+=c3;
        while(g.size() < 4*n)g+='A';
        int nr = press(g);
        if(nr == i + 1){
            ans+=c1;
        }else if(nr == i + 2){
            ans+=c2;
        }else{
            ans+=c3;
        }
    }
    string g = "";
    g+=ans;g+=c1;
    while(g.size() < 4*n)g+='A';
    if(press(g) == n)ans+=c1;
    else{
        string g = "";
        g+=ans;g+=c2;
        while(g.size() < 4*n)g+='A';
        if(press(g) == n)ans+=c2;
        else ans+=c3;
    }
    return ans;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:34:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   34 |         while(g.size() < 4*n)g+='A';
      |               ~~~~~~~~~^~~~~
combo.cpp:46:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   46 |     while(g.size() < 4*n)g+='A';
      |           ~~~~~~~~~^~~~~
combo.cpp:51:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   51 |         while(g.size() < 4*n)g+='A';
      |               ~~~~~~~~~^~~~~

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