Submission #893583

#	Time	Username	Problem	Language	Result	Execution time	Memory
893583		thunopro	Event Hopping 2 (JOI21_event2)	C++14	0 / 100	36 ms	4056 KiB

event2

#include<bits/stdc++.h>
using namespace std ;
#define maxn 200009 
#define ll long long
#define fi first 
#define se second 
#define pb push_back 
#define left id<<1
#define right id<<1|1 
#define _lower(v,x) lower_bound(v.begin(),v.end(),x)-v.begin()+1 
#define re exit(0); 

const int mod = 1e9+7 ; 
const int INF = 1e9 ; 
const int LOG = 18 ; 

typedef vector<int> vi ; 
typedef vector<ll> vl ; 
typedef pair<int,int> pii ; 
typedef vector<pii> vii ; 
typedef pair<ll,ll> pll ;  

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

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 rf () 
{
	freopen ("bai1.inp","r",stdin) ; 
//	freopen ("bai1.out","w",stdout) ; 
}

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 ; 
}

int n , k ; 
pii a [maxn] ; 

void mapping () 
{
	vi v ;
	for ( int i = 1 ; i <= n ; i ++ ) v . pb (a[i].fi) , v . pb (a[i].se) ;
	sort (v.begin(),v.end()) ; 
	v.resize(unique(v.begin(),v.end())-v.begin()) ; 
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		a [i].fi = _lower (v,a[i].fi) ; 
		a [i].se = _lower (v,a[i].se) ; 
	}
}

bool check_sub1 () 
{
	for ( int i = 1 ; i < n ; i ++ ) if ( a[i].fi > a[i+1].fi ) return false ; 
	return true ; 
}

int bit [maxn] ; 
int dp [maxn] ; 
void update ( int x , int y ) 
{
	while ( x ) chkmax (bit[x],y) , x -= (x&-x) ; 
}
int get ( int x ) 
{
	int res = 0 ; 
	while ( x < maxn ) chkmax (res,bit[x]) , x += (x&-x) ; 
	return res ; 
}
void sub1 () 
{
	for ( int i = n ; i >= 1 ; i -- ) 
	{
		dp [i] = get (a[i].se) + 1 ;
		update (a[i].fi,dp[i]) ; 
	}

	if ( get (1) < k ) 
	{
		cout << - 1 ; re 
	}
	
	int cur = 0 ; 
	vi res ;  
	
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		if ( a[i].fi >= cur && dp [i] + (int)res.size () + 1 >= k )
		{
			cur = a[i].se ; 
			res . pb (i) ;  
		}
	}
	
	for ( auto x : res ) cout << x << "\n" ; 
}
int main () 
{
	ios_base::sync_with_stdio(0) ; 
	cin.tie(0) ; cout.tie(0) ; 
//	rf () ; 
	cin >> n >> k ; 
	for ( int i = 1 ; i <= n ; i ++ ) cin >> a[i].fi >> a[i].se ; 
	mapping () ;

	if ( check_sub1 () ) sub1 () ; 

}

Compilation message (stderr)

event2.cpp: In function 'void rf()':
event2.cpp:35:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 1
• Subtask 3: 0 / 31
• Subtask 4: 0 / 61