Submission #1280760

#	Time	Username	Problem	Language	Result	Execution time	Memory
1280760		blackscreen1	Combo (IOI18_combo)	C++20	100 / 100	8 ms	468 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<long long, null_type, less<long long>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_set;
typedef tree<long long, null_type, less_equal<long long>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_multiset;
#define ll long long
#define ld long double
#define iloop(m, h) for (ll i = m; i != h; i += (m < h ? 1 : -1))
#define jloop(m, h) for (auto j = m; j != h; j += (m < h ? 1 : -1))
#define kloop(m, h) for (auto k = m; k != h; k += (m < h ? 1 : -1))
#define lloop(m, h) for (auto l = m; l != h; l += (m < h ? 1 : -1))
#define iloop_(m, h, g) for (auto i = m; i != h; i += g)
#define jloop_(m, h, g) for (auto j = m; j != h; j += g)
#define kloop_(m, h, g) for (auto k = m; k != h; k += g)
#define lloop_(m, h, g) for (auto l = m; l != h; l += g)
#define getchar_unlocked _getchar_nolock // comment before submission
#define pll pair<ll, ll>
#define plll pair<ll, pll>
#define pllll pair<pll, pll>
#define vll vector<ll>
#define qll queue<ll>
#define dll deque<ll>
#define pqll priority_queue<ll>
#define gll greater<ll>
#define INF 1000000000000000
#define MOD1 1000000007
#define MOD2 998244353
#define MOD3 1000000009
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
string guess_sequence(int N) {
	int ab = press("AB"), a, x;
	string fc, clt;
	if (ab >= 1) {
		a = press("A");
		if (a == 1) fc = "A", clt = "BXY";
		else fc = "B", clt = "AXY";
	}
	else {
		x = press("X");
		if (x == 1) fc = "X", clt = "ABY";
		else fc = "Y", clt = "ABX";
	}
	if (N == 1) return fc;
	int cptr = 1;
	int isf;
	while (cptr < N-1) {
		isf = press(fc + clt[0] + clt[0] + fc + clt[0] + clt[1] + fc + clt[1] + clt[0]);
		if (isf == cptr) {
			fc += clt[2];
			cptr++;
			continue;
		}
		if (isf == cptr+1) {
			isf = press(fc + clt[1] + clt[1]);
			if (isf == cptr) {
				fc += clt[0];
				fc += clt[2];
			}
			else if (isf == cptr + 1) {
				fc += clt[1];
				fc += clt[2];
			}
			else {fc += clt[1]; fc += clt[1];}
		}
		else if (isf == cptr+2) {
			isf = press(fc + clt[0] + clt[0]);
			if (isf == cptr) {
				fc += clt[1];
				fc += clt[0];
			}
			else if (isf == cptr + 1) {
				fc += clt[0];
				fc += clt[1];
			}
			else {fc += clt[0]; fc += clt[0];}
		}
		cptr += 2;
		//cout << fc << "," << cptr << "\n";
	}
	//cout << fc << " " << cptr << "g\n";
	if (cptr == N) return fc;
	ab = press(fc + "A" + fc + "B");
	if (ab == cptr) {
		x = press(fc + "X");
		if (x == cptr) return fc + "Y";
		else return fc + "X";
	}
	a = press(fc + "A");
	if (a == cptr) return fc + "B";
	return fc + "A";
}

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