Submission #230588

#	Time	Username	Problem	Language	Result	Execution time	Memory
230588		Dilshod_Imomov	Xylophone (JOI18_xylophone)	C++17	100 / 100	89 ms	416 KiB

xylophone

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

void solve(int n) {
	int l = 1, r = n, ind = 0, md;
	while ( l <= r ) {
		md = (l + r) / 2;
		if ( query( md, n ) == n - 1 ) {
			l = md + 1;
			ind = md;
		}
		else {
			r = md - 1;
		}
	}
	vector < int > a( n + 1 ), used(n + 1);
	a[ind] = 1;
	answer( ind, 1 );
	used[1] = 1;
	if ( ind + 1 <= n ) {
		int x = query( ind, ind + 1 );
		a[ind + 1] = x + 1;
		answer( ind + 1, x + 1 );
		used[x + 1] = 1;
	}
	if ( ind - 1 > 0 ) {
		int x = query( ind - 1, ind );
		a[ind - 1] = x + 1;
		answer( ind - 1, x + 1 );
		used[x + 1] = 1;
	}
	for ( int i = ind + 2; i <= n; i++ ) {
		int x = a[ i - 1 ], y = a[i - 2];
		int d = query( i - 1, i );
		if ( x - d < 1 || used[x - d] ) {
			a[i] = x + d;
			answer( i, x + d );
			used[x + d] = 1;
			continue;
		}
		if ( x + d > n || used[x + d] ) {
			a[i] = x - d;
			answer( i, x - d );
			used[x - d] = 1;
			continue;
		}
		int q = query( i - 2, i );
		int mx = max( { x, y, x - d } ), mn = min( { x, y, x - d } );
		if ( q == mx - mn ) {
			a[i] = x - d;
			answer( i, x - d );
			used[x - d] = 1;
		}
		else {
			a[i] = x + d;
			answer( i, x + d );
			used[x + d] = 1;
		}
	}
	for ( int i = ind - 2; i > 0; i-- ) {
		int x = a[ i + 1 ], y = a[i + 2];
		int d = query( i, i + 1 );
		if ( x - d < 1 || used[x - d] ) {
			a[i] = x + d;
			answer( i, x + d );
			used[x + d] = 1;
			continue;
		}
		if ( x + d > n ) {
			a[i] = x - d;
			answer( i, x - d );
			used[x - d] = 1;
			continue;
		}
		int q = query( i, i + 2 );
		int mx = max( { x, y, x - d } ), mn = min( { x, y, x - d } );
		if ( q == mx - mn ) {
			a[i] = x - d;
			answer( i, x - d );
			used[x - d] = 1;
		}
		else {
			a[i] = x + d;
			answer( i, x + d );
			used[x + d] = 1;
		}	
	}
}

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