Submission #713078

#	Time	Username	Problem	Language	Result	Execution time	Memory
713078		hoainiem	Combo (IOI18_combo)	C++14	30 / 100	50 ms	616 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
using namespace std;
string vt, st;
pair<int, int>ds[3]{{0, 1}, {0, 2}, {1, 2}};
string s[3];
int k, mask;
std::string guess_sequence(int n) {
    string ans;
    srand(time(NULL));
    k = press("AB");
    if (k == 2)
        ans = "AB";
    else{
        if (k == 1){
            if (press("A"))
                ans = "A";
            else
                ans = "B";
        }
        else{
            if (press("X"))
                ans = "X";
            else
                ans = "Y";
        }
    }
    vt = {'A', 'B', 'X', 'Y'};
    for (int i = 0; i < 4; i++)
        if (vt[i] == ans[0]){
            vt.erase(vt.begin() + i);
            break;
        }
    mask = vt[0] ^ vt[1] ^ vt[2];
    s[0] = (st + vt[0]) + vt[1];
    s[1] = (st + vt[0]) + vt[2];
    s[2] = (st + vt[1]) + vt[2];
    while ((int)ans.size() < n){
        int sz = ans.size();
        if (n - (int)ans.size() == 1){
            if (press(ans + vt[0]) == n)
                return ans + vt[0];
            else{
                if(press(ans + vt[1]) == n)
                    return ans + vt[1];
                return ans + vt[2];
            }
        }
        string op = s[rand() % 3];
        char u = op[0], v = op[1];
        k = press(ans + u + u + ans + u + v + ans + v + u + ans + v + v);
        if (k == sz)
            ans.push_back((char)(mask ^ op[0] ^ op[1]));
        else{
            if (k - sz == 1){
                char nct = mask ^ op[0] ^ op[1];
                if (press(ans + u + nct) == sz + 2)
                    ans = ans + u + nct;
                else
                    ans = ans + v + nct;
            }
            else{
                int tmp = press(ans + u + u + ans + v + v);
                if (tmp - sz == 2){
                    if (press(ans + u + u) == sz + 2)
                        ans = ans + u + u;
                    else
                        ans = ans + v + v;
                }
                else{
                    if (press(ans + u + v) == sz + 2)
                        ans = ans + u + v;
                    else
                        ans = ans + v + u;
                }
            }
        }
    }
    return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95