Submission #1279255

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279255		Iwantbemaster	Combo (IOI18_combo)	C++20	0 / 100	7 ms	476 KiB

combo

#include <bits/stdc++.h>
#include "combo.h"
using namespace std;
//signed main(){ // clock_t the_time = clock(); double t_;
//	IO(""); int n, result = 0; cin >> n;
//    vector<int > a(n), b(n), c(n);
//    for(auto &to : a) cin >> to;
//    for(auto &to : b) cin >> to;
//    for (int i = 0; i < n; i++) c[i] = a[i] - b[i];
//    sort(c.begin(), c.end());
//    auto UPPB = [&](long long x) -> int {
//        int l = 0, r = n;
//        while(l < r){
//            int m = (l + r) / 2;
//            if(c[m] <= x) l = m + 1;
//            else r = m;
//        } return l;
//    }; for(int i = 0; i < n; i++){
//        result += n - UPPB(-c[i]);
//        if(UPPB(-c[i]) <= i) result--;
//    } cout << result / 2;
//    // t_ = double(clock() - the_time) / CLOCKS_PER_SEC; cout << fixed << setprecision(16)<<  t_ << " sec.";
//}
string guess_sequence(int N) {
    string s; vector<char> res_;
    if(press("AB") > 0){
        if(press("A") > 0) s = "A";
        else s = "B";
    } else {
        if(press("X") > 0) s = "X";
        else s = "Y";
    } if(N == 1){ return s; }
    for(char c : {'A', 'B', 'X', 'Y'}) {
        if(c != s[0]) res_.emplace_back(c);
    } for(int i = 1; i < N - 1; i++){
        string str = s + res_[0] + s + res_[1] + res_[0] + s + res_[1] + res_[1] + s + res_[2];
        int res = press(str);
        if(res == i) s += res_[2];
        else if(res == i + 1) s += res_[0];
        else s += res_[1];
    } if(press(s + res_[0]) == N) s += res_[0];
    else if(press(s + res_[1]) == N) s += res_[1];
    else s += res_[2];
    return s;
}

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