Submission #887924

#	Time	Username	Problem	Language	Result	Execution time	Memory
887924		thunopro	Arranging Shoes (IOI19_shoes)	C++14	45 / 100	29 ms	12624 KiB

shoes

#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 re exit(0); 

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

typedef vector<int> vi ; 
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 (int &a , int b) { if (a>b) a=b ;} 
template < typename T > void chkmax (int &a , int b) { if (a<b) a=b ;}

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

int n ; 
int a [maxn] ; 
vi shoes [maxn] ; 

int bit [maxn] ;
void update ( int x ) 
{
	while ( x ) bit [x] ++ , x -= (x&-x) ;
}
int get ( int x ) 
{
	int res = 0 ; 
	while ( x < maxn ) res += bit [x] , x += (x&-x) ; 
	return res ; 
}
ll count_swaps ( vi _a ) 
{
	n = _a.size () ;
	for ( int i = 1 ; i <= n ; i ++ ) a [i] = _a [i-1] ; 
	for ( int i = n ; i >= 1 ; i -- ) if ( a [i] > 0 ) shoes [a[i]] . pb (i) ; 
	
	ll res = 0 ; 
	int cur = 1 ; 
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		if ( a [i] < 0 ) 
		{
			res += get (i) + i - cur ; cur ++ ; 
			update (i) ; 
			int pos = shoes[-a[i]].back () ; shoes[-a[i]].pop_back () ; 
			res += get (pos) + pos - cur ; cur ++ ;
			update (pos) ; 
		}
	}
	return res ; 
}

Compilation message (stderr)

shoes.cpp: In function 'void rf()':
shoes.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15