Submission #75004

#	Time	Username	Problem	Language	Result	Execution time	Memory
75004		ainta	Combo (IOI18_combo)	C++17	100 / 100	103 ms	528 KiB

combo

#include "combo.h"
#include <algorithm>
#include <string>
using namespace std;

char s[5] = "ABXY";

string p, res;

void Put(int pv) {
	p += s[pv];
}
void Clear() {
	p = "";
}

std::string guess_sequence(int N) {
	int i, st = -1, j;
	Clear();
	for (int i = 0; i < 2 * N; i++) Put(0);
	for (int i = 0; i < 2 * N; i++) Put(1);
	int t = press(p);
	if (t) {
		Clear();
		for (i = 0; i < 4 * N; i++)Put(0);
		t = press(p);
		if (t)st = 0;
		else st = 1;
	}
	else {
		Clear();
		for (i = 0; i < 4 * N; i++)Put(2);
		t = press(p);
		if (t)st = 2;
		else st = 3;
	}
	res = "";
	res += s[st];
	if (N == 1)return res;

	int p1 = (st + 1) % 4;
	int p2 = (st + 2) % 4;
	int p3 = (st + 3) % 4;
	for (i = 2; i < N; i++) {
		Clear();
		p += res;
		Put(p1);
		for (j = 0; j < N - i; j++)Put(p1);
		p += res;
		Put(p1);
		for (j = 0; j < N - i; j++)Put(p2);
		p += res;
		Put(p1);
		for (j = 0; j < N - i; j++)Put(p3);
		p += res;
		Put(p2);
		for (j = 0; j < N - i; j++)Put(st);
		t = press(p);
		if (t == i - 1)res += s[p3];
		else if (t == i)res += s[p2];
		else res += s[p1];
	}
	Clear();
	p += res;
	Put(p1);
	for (i = 0; i < 3 * N; i++)Put(st);
	t = press(p);
	if (t == N)res += s[p1];
	else {
		Clear();
		p += res;
		Put(p2);
		for (i = 0; i < 3 * N; i++)Put(st);
		t = press(p);
		if (t == N)res += s[p2];
		else res += s[p3];
	}
	return res;
}

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