Submission #359315

#	Time	Username	Problem	Language	Result	Execution time	Memory
359315		shahriarkhan	Xylophone (JOI18_xylophone)	C++14	0 / 100	1 ms	492 KiB

xylophone

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

void solve(int N) {

	int A[N+2] = {0} , vis[N+2] = {0} , low = 1 , high = N ;
	int k;
	int lo=1;
	int hi=N;
	while(lo<=hi)
	{
		int mid=lo+hi>>1;

		if(query(mid,N)==N-1)
		{
			lo=mid+1;
		}
		else
		{
			k=mid;
			hi=mid-1;
		}

	}
    low = k - 1 ;
    A[low] = 1 , vis[1] = 1 ;
    for(int i = low - 1 ; i >= 1 ; --i)
    {
        int temp = query(i,i+1) , left = A[i+1] - temp , right = A[i+1] + temp ;
        if((left<=0) || vis[left])
        {
            vis[right] = 1 ;
            A[i] = right ;
        }
        else if((right>N) || vis[right])
        {
            vis[left] = 1 ;
            A[i] = left ;
        }
        else
        {
            temp = query(i,i+2) ;
            if((max(left,A[i+2])-min(A[i+1],A[i+2]))==temp)
            {
                vis[left] = 1 ;
                A[i] = left ;
            }
            else
            {
                vis[right] = 1 ;
                A[i] = right ;
            }
        }
    }
    for(int i = low + 1 ; i <= N ; ++i)
    {
        int temp = query(i-1,i) , left = A[i-1] - temp , right = A[i-1] + temp ;
        if((left<=0) || vis[left])
        {
            vis[right] = 1 ;
            A[i] = right ;
        }
        else if((right>N) || vis[right])
        {
            vis[left] = 1 ;
            A[i] = left ;
        }
        else
        {
            temp = query(i-2,i) ;
            if((max(left,A[i-2])-min(A[i-1],A[i-2]))==temp)
            {
                vis[left] = 1 ;
                A[i] = left ;
            }
            else
            {
                vis[right] = 1 ;
                A[i] = right ;
            }
        }
    }
	for(int i = 1; i <= N; i++)
    {
		answer(i, A[i]) ;
	}
}

Compilation message (stderr)

xylophone.cpp: In function 'void solve(int)':
xylophone.cpp:13:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   13 |   int mid=lo+hi>>1;
      |           ~~^~~
xylophone.cpp:7:48: warning: unused variable 'high' [-Wunused-variable]
    7 |  int A[N+2] = {0} , vis[N+2] = {0} , low = 1 , high = N ;
      |                                                ^~~~
xylophone.cpp:8:6: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
    8 |  int k;
      |      ^

• Subtask 1: 0 / 11
• Subtask 2: 0 / 36
• Subtask 3: 0 / 53