Submission #895935

#	Time	Username	Problem	Language	Result	Execution time	Memory
895935		thunopro	Evacuation plan (IZhO18_plan)	C++14	100 / 100	661 ms	48872 KiB

plan

#include<bits/stdc++.h>
using namespace std ; 
#define ll long long 
#define maxn 200009 
#define fi first 
#define se second 
#define pb push_back 
#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  

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

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

vii adjList [maxn] ;
struct query {
	int s , t ;
}q [maxn] ; 
int d [maxn] ; 
pii vertex [maxn] ; 

struct shape {
	int u , d ; 
	bool operator < ( const shape &o ) const {
		return d>o.d ; 
	}
};
void prepare () 
{
	priority_queue <shape> S ; 
	memset ( d , 0x3f , sizeof d ) ; 
	int num ; cin >> num ; 
	for ( int i = 1 ; i <= num ; i ++ ) 
	{
		int x ; cin >> x ; 
		S . push ({x,d[x]=0}) ; 
	}
	
	while (!S.empty()) 
	{
		shape t = S.top() ; S.pop() ; 
		int u =t.u ; 
		if (t.d!=d[u]) continue ; 
		for ( auto x : adjList [u] ) 
		{
			int v =x.fi , w=x.se ; 
			if ( d[v] >d[u]+w) S . push ({v,d[v]=d[u]+w}) ; 
		}
	}
	for ( int i = 1 ; i <= n ; i ++ ) vertex [i] = {d[i],i} ; 
	sort (vertex+1,vertex+n+1,greater<pii>()) ; 
}

vi to_check [maxn] ; 
int L [maxn] , R [maxn] ; 

int lab [maxn] ; 
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 ; 
}

bool used [maxn] ; 
void add_vertex ( int u ) 
{
	for ( auto x : adjList [u] ) 
	{
		int v = x.fi ; 
		if ( used [v] ) uni (u,v) ; 
	}
}
int main () 
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);cout.tie(0) ; 
//	rf () ; 
	cin >> n >> m ; 
	for ( int i = 1 ; i <= m ; i ++ ) 
	{
		int u , v , w ; cin >> u >> v >> w ; 
		adjList [u] . pb ({v,w}) ; 
		adjList [v] . pb ({u,w}) ; 
	}
	
	prepare () ; 
	
	cin >> nq ; 
	for ( int i = 1 ; i <= nq ; i ++ ) 
	{
		cin >> q[i].s >> q [i].t ; 
	}
	
	for ( int i = 1 ; i <= nq ; i ++ ) L [i] = 1 , R [i] = n ; 

	while ( true )
	{
		bool changed = false ; 
		for ( int i = 1 ; i <= nq ; i ++ ) 
		{
			if ( L[i]!=R[i] ) 
			{
				to_check [(L[i]+R[i])/2] . pb (i) ; 
				changed = true ; 
			}
		}
		for ( int i = 1 ; i <= n ; i ++ ) lab [i] = - 1 , used [i] = false ; 
		
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			used [vertex[i].se] = true ; 
			add_vertex (vertex[i].se) ; 
			while (!to_check[i].empty()) 
			{
				int id = to_check[i].back() ; to_check[i].pop_back() ; 
				if ( find (q[id].s) == find (q[id].t) ) R[id] = i ; 
				else L [id] = i+1 ;  
			}
		}
		if ( changed == false ) break ; 
	}
	
	for ( int i = 1 ; i <= nq ; i ++ ) cout << vertex[L[i]].fi << "\n" ; 
}

// range , error , check speical , ... 
// find key , find key 
//'-std=c++11' stay hard 
// there is no tomorrow 

Compilation message (stderr)

plan.cpp: In function 'void rf()':
plan.cpp:34:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46