Submission #1122364

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122364		khome	Combo (IOI18_combo)	C++14	5 / 100	2 ms	508 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
 
using namespace std;
 
string guess_sequence(int N) {
    vector<char> a;
    a={'X', 'Y', 'A', 'B'};
    string res, cur;
    int ab = press("AB"), bx = press("BX"), id=2;
    if (ab == 2) {
        id = 2;
        res = "AB";
    }
    if (ab == 1) {
        if (bx == 1) { //BX = 1;
            id=3;
            int by = press("BY"); 
            if (by == 2) res = "BY";
            else res = "BA";
        } 
        if (bx == 2) {
            id = 3;
            res += "BX";
        }
        if (bx == 0) { // BX = 0; AY, AX
            id = 2;
            int ay = press("AY");
            if (ay == 2) res = "AY";
            else res = "AX";
        }
    }
    else if (ab == 0) {
        if (bx == 1) { // XA, XB, XY
            id = 0;
            int xa = press("XAAXABXAYXB");
            if (xa == 3) res = "XA";
            else if (xa == 2) res = "XB";
            else res = "XY";
        }
        else { // YA, YB, YX
            id = 1;
            int yb = press("YAAYABYAXYB");
            if (yb == 3) res = "YA";
            else if (yb == 2) res = "YB";
            else res = "YX";
        }
    }
    
 
    int n = res.size();
    if (N==3){
        int x = press(res+a[(id+1)%4]), y = press(res+a[(id+2)%4]);
        if (x == 3) return res+a[(id+1)%4];  
        else if (y == 3) return res+a[(id+2)%4];  
        else return res+a[(id+3)%4];  
    }
  else{
        char c = a[(id+1)%4], d = a[(id+2)%4], e = a[(id+3)%4];
        int ask;
        while (n!=N-1){
            n=res.size();
            if (n==N-1) break;
            ask = press(res+c+c+res+c+d+res+c+e+res+d);
            if (ask == n+2) res += c;
            else if (ask == n+1) res += d;
            else res += e;
        }
        ask = press(res+c);
        if (ask == N)  res+=c;
        else{
            int ask2 = press(res+d);
            if (ask2 == N) res+=d;
            else res+=e;}
        return res;
  }
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95