Submission #1116940

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116940		tuandq	Combo (IOI18_combo)	C++17	100 / 100	46 ms	1644 KiB

combo

#include <bits/stdc++.h>
using namespace std ;

int press(std::string p);

string guess_sequence(int n) {
    vector<string> a = {"A", "B", "X", "Y"} ;

    string res = "", h = "" ;

    if(press(a[0] + a[1])) {
        h = (press(a[0]) ? a[0] : a[1]) ;
    }
    else {
        h = (press(a[2]) ? a[2] : a[3]) ;
    }
    a.erase(find(a.begin(), a.end(), h)) ;
    res += h ;

    for(int i = 1; i < n; i ++) {
        // cerr << i << ' ' ;
        if(i == n - 1) {
            if(press(res + a[0]) == i + 1) res += a[0] ;
            else res += (press(res + a[1]) == i + 1 ? a[1] : a[2]) ;
            break ;
        }

        int x = press(res+a[0]+a[0] + res+a[0]+a[1] + res+a[1]+a[0]) ;
        if(x == i) {
            res += a[2] ; continue ;
        }
        if(x == i + 1) {
            int y = press(res + a[1] + a[1]) ;
            if(y == i) {
                res += a[0] + a[2] ;
            }
            else if(y == i + 1) {
                res += a[1] + a[2] ;
            }
            else {
                res += a[1] + a[1] ;
            }
        }
        else {
            int y = press(res + a[0] + a[0]) ;
            if(y == i) {
                res += a[1] + a[0] ;
            }
            else if(y == i + 1) {
                res += a[0] + a[1] ;
            }
            else {
                res += a[0] + a[0] ;
            }
        } ++ i ;
    }
    
    return res ;
}

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