Submission #1116612

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116612		gustavo_d	Xylophone (JOI18_xylophone)	C++17	100 / 100	201 ms	956 KiB

xylophone

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

int a1[5001], a2[5001];

void solve(int N) {
	int n = N;
	int pos1=1;
	a1[pos1] = 1;
	a2[pos1] = 1;
	a1[pos1+1] = 1-query(pos1, pos1+1);
	a2[pos1+1] = query(pos1, pos1+1) + 1;
	for (int pt = pos1+2; pt<=n; pt++) {
		int q1 = query(pt-1, pt), q2 = query(pt-2, pt);

		int d1 = abs(a1[pt-1] - a1[pt-2]);
		int d = q1;
		if (a1[pt-2] < a1[pt-1]) {
			if (q2 == d + d1) a1[pt] = a1[pt-1] + d;
			else a1[pt] = a1[pt-1] - d;
		} else {
			if (q2 == d + d1) a1[pt] = a1[pt-1] - d;
			else a1[pt] = a1[pt-1] + d;
		}
		d1 = abs(a2[pt-1] - a2[pt-2]);
		if (a2[pt-2] < a2[pt-1]) {
			if (q2 == d + d1) a2[pt] = a2[pt-1] + d;
			else a2[pt] = a2[pt-1] - d;
		} else {
			if (q2 == d + d1) a2[pt] = a2[pt-1] - d;
			else a2[pt] = a2[pt-1] + d;
		}
	}
	int mn = 1e9;
	for (int i=1; i<=n; i++) mn = min(mn, a1[i]);
	for (int i=1; i<=n; i++) a1[i] -= mn-1;
	mn = 1e9;
	for (int i=1; i<=n; i++) mn = min(mn, a2[i]);
	for (int i=1; i<=n; i++) a2[i] -= mn-1;
	// int pos1=n;
	// for (; pos1>=1; pos1--) {
	// 	int value = query(pos1, n);
	// 	if (value == n-1) break;
	// }
	// a[pos1] = 1;
	// a[pos1+1] = query(pos1, pos1+1) + 1;
	// for (int pt = pos1+2; pt<=n; pt++) {
	// 	int d1 = abs(a[pt-1] - a[pt-2]);
	// 	int d = query(pt-1, pt);
	// 	if (a[pt-2] < a[pt-1]) {
	// 		if (query(pt-2, pt) == d + d1) a[pt] = a[pt-1] + d;
	// 		else a[pt] = a[pt-1] - d;
	// 	} else {
	// 		if (query(pt-2, pt) == d + d1) a[pt] = a[pt-1] - d;
	// 		else a[pt] = a[pt-1] + d;
	// 	}
	// }
	// for (int pt = pos1-1; pt>=1; pt--) {
	// 	int d1 = abs(a[pt+1] - a[pt+2]);
	// 	int d = query(pt, pt+1);
	// 	if (a[pt+2] < a[pt+1]) {
	// 		if (query(pt, pt+2) == d + d1) a[pt] = a[pt+1] + d;
	// 		else a[pt] = a[pt+1] - d;
	// 	} else {
	// 		if (query(pt, pt+2) == d + d1) a[pt] = a[pt+1] - d;
	// 		else a[pt] = a[pt+1] + d;
	// 	}
	// }

	bool a1_ac = true;
	bool found1 = false;
	for (int i=1; i<=n; i++) {
		if (a1[i] == 1) found1 = true;
		if (a1[i] == n and !found1) a1_ac = false;
	}
	for(int i = 1; i <= N; i++) {
		answer(i, a1_ac ? a1[i] : a2[i]);
	}
}

• Subtask 1: 11 / 11
• Subtask 2: 36 / 36
• Subtask 3: 53 / 53