제출 #1311740

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1311740		madamadam3	Xylophone (JOI18_xylophone)	C++20	100 / 100	29 ms	668 KiB

xylophone

#include "xylophone.h"
#include <bits/stdc++.h>

using namespace std;

static int A[5000];

void solve(int N) {
	int value = query(1, N);
	int L = 1, R = N;
	
	int lo = 1, hi = N;
	while (lo < hi) {
		int mid = lo + (hi - lo) / 2;
		if (query(1, mid) == value) {
			hi = mid;
		} else {
			lo = mid + 1;
		}
	}

	R = lo;
	lo = 1, hi = N;
	while (lo < hi) {
		int mid = lo + (hi - lo + 1) / 2;
		if (query(mid, N) == value) {
			lo = mid;
		} else {
			hi = mid - 1;
		}
	}
	L = lo;

	// cerr << "L: " << L << " R: " << R << "\n";

	vector<int> ans(N+1, -1);
	set<int> avail; for (int i = 1; i <= N; i++) avail.insert(i);
	avail.erase(1); avail.erase(N);

	ans[L] = 1; ans[R] = N;
	for (int i = L+1; i < R; i++) {
		if (i == L+1) {
			ans[i] = 1 + query(L, i);
			// cerr << "Options for " << i << " are " << ans[i] << "\n";
		} else {
			int dx = query(i-1, i);
			int a = ans[i-1] + dx, b = ans[i-1] - dx;
			int x = ans[i-2], y = ans[i-1];
			// cerr << "Options for " << i << " are " << a << " and " << b << "\n";
			// cerr << "i: " << i << " dx: " << dx << " dy: " << dy << " a: " << a << " b: " << b << " x: " << x << " y: " << y << "\n";

			// y < a < x, y < x < a, x < y < a
			// x < b < y, b < y < x, b < x < y
			if (!avail.count(a)) ans[i] = b;
			else if (!avail.count(b)) ans[i] = a;
			else {
				int dy = query(i-2, i);
				if (y < a && a < x && dy == x-y) ans[i] = a;
				else if (y < x && x < a && dy == a-y) ans[i] = a;
				else if (x < y && y < a && dy == a-x) ans[i] = a;
				else if (x < b && b < y && dy == y-x) ans[i] = b;
				else if (b < y && y < x && dy == x-b) ans[i] = b;
				else if (b < x && x < y && dy == y-b) ans[i] = b;
			}
		}

		avail.erase(ans[i]);
	}

	for (int i = L-1; i >= 1; i--) {
		if (i == L-1) {
			ans[i] = 1 + query(i, L);
		} else {
			int dx = query(i, i+1);
			int a = ans[i+1] + dx, b = ans[i+1] - dx;
			int x = ans[i+2], y = ans[i+1];

			// y < a < x, y < x < a, x < y < a
			// x < b < y, b < y < x, b < x < y
			if (!avail.count(a)) ans[i] = b;
			else if (!avail.count(b)) ans[i] = a;
			else {
				int dy = query(i, i+2);
				if (y < a && a < x && dy == x-y) ans[i] = a;
				else if (y < x && x < a && dy == a-y) ans[i] = a;
				else if (x < y && y < a && dy == a-x) ans[i] = a;
				else if (x < b && b < y && dy == y-x) ans[i] = b;
				else if (b < y && y < x && dy == x-b) ans[i] = b;
				else if (b < x && x < y && dy == y-b) ans[i] = b;
			}
		}

		avail.erase(ans[i]);
	}

	for (int i = R+1; i <= N; i++) {
		if (i == R+1) {
			ans[i] = N - query(R, i);
		} else {
			int dx = query(i-1, i);
			int a = ans[i-1] + dx, b = ans[i-1] - dx;
			int x = ans[i-2], y = ans[i-1];

			// y < a < x, y < x < a, x < y < a
			// x < b < y, b < y < x, b < x < y
			if (!avail.count(a)) ans[i] = b;
			else if (!avail.count(b)) ans[i] = a;
			else {
				int dy = query(i-2, i);
				if (y < a && a < x && dy == x-y) ans[i] = a;
				else if (y < x && x < a && dy == a-y) ans[i] = a;
				else if (x < y && y < a && dy == a-x) ans[i] = a;
				else if (x < b && b < y && dy == y-x) ans[i] = b;
				else if (b < y && y < x && dy == x-b) ans[i] = b;
				else if (b < x && x < y && dy == y-b) ans[i] = b;
			}
		}

		avail.erase(ans[i]);
	}

	// for (int i = 1; i <= N; i++) cerr << ans[i] << " ";
	// cerr << "\n";

	for(int i = 1; i <= N; i++) {
		answer(i, ans[i]);
	}
}

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