Submission #958304

#	Time	Username	Problem	Language	Result	Execution time	Memory
958304		thunopro	Swapping Cities (APIO20_swap)	C++14	37 / 100	2068 ms	13140 KiB

swap

#include<bits/stdc++.h>
using namespace std ;
#define maxn 250009 
#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()/CLOCK_PERS_SEC) 

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

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

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

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 ; 
}

mt19937 rng(time(0)) ; 

//#include "grader.h" 

int n , m ; 
vi u , v , w ; 
int lab [maxn] , deg [maxn] ; 

struct shape {
	int u , v , w ; 
}e[maxn];
bool cmp ( shape u , shape v ) 
{
	return u.w < v.w ; 
}

void init ( int N , int M , vi U , vi V , vi W ) 
{
	n = N , m = M ; 
	for ( int i = 0 ; i < m ; i ++ ) 
	{
		U [i] ++ , V [i] ++ ; 
		e [i+1] = {U[i],V[i],W[i]} ; 
	}
	sort (e+1,e+m+1,cmp) ; 
}

int find ( int u ) 
{
	return (lab[u]<0?u:lab[u]=find(lab[u])) ; 
}
void uni ( int u , int v ) 
{
	if ((u=find(u)) == (v=find(v))) return ; 
	if ( lab [u] > lab [v] ) swap (u,v) ; 
	lab [u] += lab [v] ;
	lab [v] = u ; 
}

int getMinimumFuelCapacity ( int x , int y ) 
{
	x ++ , y ++ ; 
	int l = 1 , r = m ; 
	int res = -1 ; 
	while ( l <= r ) 
	{
		for ( int i = 1 ; i <= n ; i ++ ) lab [i] = -1 , deg [i] = 0 ; 
		int mid = (l+r)/2 ; 
		bool ok = false ; 
		for ( int i = 1 ; i <= mid ; i ++ )
		{
			if (find(e[i].u) == find(e[i].v) && find(e[i].u) == find(x) && find(e[i].u) == find(y)) ok = true ; 
			deg [e[i].u] ++ , deg [e[i].v] ++ ; 
			uni (e[i].u,e[i].v) ; 
		}
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			if ( deg [i] >= 3 && find (i) == find (x) && find (i) == find (y) ) ok = true ; 
		}
		if ( ok == true ) res = e[mid].w , r = mid-1 ; 
		else l = mid+1 ; 
	}
	return res ; 
}

//int main () 
//{
//	init(5, 6, {0, 0, 1, 1, 1, 2}, {1, 2, 2, 3, 4, 3}, {4, 4, 1, 2, 10, 3}); 
//	cout << getMinimumFuelCapacity(1,2) ; 
//}

Compilation message (stderr)

swap.cpp: In function 'void rf()':
swap.cpp:33:9: 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: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27