Submission #1040370

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040370		vjudge1	Evacuation plan (IZhO18_plan)	C++14	41 / 100	4033 ms	30352 KiB

plan

#include<bits/stdc++.h>
using namespace std ; 
#define maxn 500009
#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
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) ;
}

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] ; 
int k ; 
int f [maxn] ; 

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

pii p [maxn] ; 
bool cmp ( pii u , pii v ) 
{
	return u.fi > v.fi ; 
}

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 ; 
}

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}) ;
	}
	cin >> k ; 
	for ( int i = 1 ; i <= k ; i ++ ) cin >> f [i] ; 

	dijkstra () ; 
	
//	for ( int i = 1 ; i <= n ; i ++ ) cout << d [i] << " " ; re
	for ( int i = 1 ; i <= n ; i ++ ) p [i] = {d[i],i} ; 
	sort (p+1,p+n+1,cmp) ; 
		
	cin >> nq ; 
	while ( nq -- ) 
	{
		int x,y ; cin >> x >> y ; 
		for ( int i = 1 ; i <= n ; i ++ ) lab [i] = -1 ;
		int res ;  
		for ( int i = 1 ; i <= n ; i ++ ) 
		{
			int u = p[i].se ; 
			for ( auto v : adjList [u] ) 
			{
				if ( d [v.fi] >= d [u] ) uni (u,v.fi) ; 
			}
			if ( find(x) == find(y) ) 
			{
				res = p[i].fi ; break ; 
			}
		}
		cout << res << "\n" ; 
	}
}

Compilation message (stderr)

plan.cpp: In function 'void rf()':
plan.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
plan.cpp: In function 'int main()':
plan.cpp:134:18: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
  134 |   cout << res << "\n" ;
      |                  ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 0 / 46