Submission #803726

#	Time	Username	Problem	Language	Result	Execution time	Memory
803726		ALeonidou	Combo (IOI18_combo)	C++17	Compilation error	0 ms	0 KiB

combo

#include "combo.h"
using namespace std;
 
#define ll long long
string guess_sequence(int n) {
    string p, s = "";
    string w = "ABXY";

    if (n == 1){
        ll a = press("A"), b = press("B"), x = press("X");
        if (a) return "A";
        else if (b) return "B";
        else if (x) return "X";
        return "Y";
    }
 
    //find first letter (3 operations)
    ll f = 0, x = press("AB");
    if (x){
        x = press("A");
        if (x) f= 0;
        else f = 1;
    } 
    else{
        x = press("X");
        if (x) f = 2;
        else f = 3;
    }
    s += w[f];
    w.erase(w.begin() + f);
 
    if (n == 1) return s;
 
    //find all letters until n-1 (n-2 operations)
    for (ll i =1; i<n-1; i++){
        p = s + w[0] + s + w[1] + w[0] + s + w[1] + w[1] + s + w[1] + w[2];
        x = press(p);
        if (x == i) s += w[2];
        else if (x == i+1) s += w[0];
        else s += w[1];
    }
 
    //find last letter (2 operations)
    a = press(s + w[0]), b = press(s + w[1]);
    if (a == b) s += w[2];
    else if (a > b) s += w[0];
    else s += w[1]; 
 
    return s;    
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:44:5: error: 'a' was not declared in this scope
   44 |     a = press(s + w[0]), b = press(s + w[1]);
      |     ^
combo.cpp:44:26: error: 'b' was not declared in this scope
   44 |     a = press(s + w[0]), b = press(s + w[1]);
      |                          ^