Submission #944039

#	Time	Username	Problem	Language	Result	Execution time	Memory
944039		thunopro	Chameleon's Love (JOI20_chameleon)	C++14	100 / 100	50 ms	616 KiB

chameleon

#include<bits/stdc++.h>
using namespace std ; 
#define maxn 200009
#define ll long long 
#define pb push_back 
#define fi first 
#define se second 
#define left id<<1
#define right id<<1|1 
#define re exit(0); 
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()+1 
#define TIME ( 1.0*clock() / CLOCKS_PER_SEC )
const int mod = 1e9+7 ;
const int INF = 1e9 ; 

typedef vector<int> vi ; 
typedef pair<int,int> pii ; 
typedef vector<pii> vii ; 

template < typename T > void chkmin ( T &a , T b ) { if ( a > b ) a = b ; } 
template < typename T > void chkmax ( T &a , T b ) { if ( a < b ) a = b ; } 

void add ( int &a , int b ) 
{
	a += b ; 
	if ( a >= mod ) a -= mod ; 
	if ( a < 0 ) a += mod ; 
}

void rf () 
{
	freopen ("bai1.inp","r",stdin) ;
}

mt19937 rng (time(0)) ; 

int _pow ( int a , int n ) 
{
	if ( n == 0 ) return 1 ; 
	int res = _pow (a,n/2) ; 
	if ( n % 2 ) return 1ll*res*res%mod*a%mod ; 
	else return 1ll*res*res%mod ; 
}

#include "chameleon.h"
bool bad ( vi v , int x ) 
{
	v . pb (x) ; 
	return Query (v) != v.size () ; 
}

void Solve ( int n ) 
{
	vi adj [2*n+5] ; 
	for ( int cr = 1 ; cr <= 2*n ; cr ++ ) 
	{
		vi colour (cr) , inset [2] ; 
		function<void(int,int)> dfs = [&] ( int nw , int cl ) 
		{
			if ( colour [nw] ) return ; 
			colour [nw] = cl ; 
			for ( auto nx : adj [nw] ) dfs (nx,3-cl) ; 
		}; 
		
		for ( int i = 1 ; i < cr ; i ++ ) 
		{
			if ( !colour [i] ) dfs (i,1) ; 
			inset [colour[i]-1] . pb (i) ; 
		}
		
		for ( int i = 0 ; i < 2 ; i ++ ) 
		{
			while ( bad(inset[i],cr) ) 
			{
				int lf = 1 , rg = inset[i].size () ; 
				for ( int md ; lf < rg ; ) 
				{
					md = (lf+rg)/2 ; 
					if ( bad(vi(inset[i].begin(),inset[i].begin()+md),cr)) rg = md ; 
					else lf = md+1 ; 
				}
				adj [cr] . pb (inset[i][lf-1]) ; 
				adj [inset[i][lf-1]] . pb (cr) ; 
				
				inset [i] = vi (inset[i].begin()+lf,inset[i].end()) ; 
			}
		}
	}
	vi same (2*n+5) , n1 (2*n+5) , n2 (2*n+5) ; 
	for ( int i = 1 ; i <= 2*n ; i ++ ) 
	{
		if ( adj [i].size () == 1 ) same [i] = adj [i][0] ; 
		else 
		{
			while ( Query ({i,adj[i][0],adj[i][1]}) != 1 ) 
			{
				rotate (adj[i].begin(),adj[i].begin()+1,adj[i].end()) ; 
			}
			n1 [i] = adj [i][2] ; 
			n2 [adj[i][2]] = i ; 
		}
	}
	
	for ( int i = 1 ; i <= 2*n ; i ++ ) 
	{
		if ( !same[i] ) 
		{
			same [i] = adj [i][0] + adj [i][1] + adj [i][2] - n1 [i] - n2 [i] ; 
		}
		if ( i > same [i] ) Answer (same[i],i) ; 
	}
	return ; 
}
//int main () 
//{
//	ios_base::sync_with_stdio(0); 
//	cin.tie(0);cout.tie(0); 
////	rf () ;
//	
//}

Compilation message (stderr)

chameleon.cpp: In function 'bool bad(vi, int)':
chameleon.cpp:49:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |  return Query (v) != v.size () ;
      |         ~~~~~~~~~~^~~~~~~~~~~~
chameleon.cpp: In function 'void rf()':
chameleon.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 36 / 36