| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 339294 | Dilshod_Imomov | Evacuation plan (IZhO18_plan) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
# include <bits/stdc++.h>
# define speed ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
# define int long long
# define fi first
# define se second
using namespace std;
const int N = 2e6 + 7;
const int mod = 1e9 + 7;
vector < pair < int, int > > adj[N];
int dist[N], n, m, go, pr[N], ans[N], size[N];
bool used[N];
set < int > st[N];
int find_set( int a ) {
if ( a == pr[a] ) {
return a;
}
return find_set(pr[a]);
}
void merge( int a, int b, int val ) {
int x = find_set(a);
int y = find_set(b);
if ( x == y ) {
return;
}
if ( size[x] < size[y] ) {
swap( x, y );
}
for ( auto i: st[y] ) {
if ( st[x].count(i) ) {
ans[ i ] = val;
}
else {
st[x].insert(i);
}
}
st[y].clear();
pr[y] = x;
size[x] += size[y];
}
int32_t main() {
speed;
cin >> n >> m;
for ( int i = 1; i <= m; i++ ) {
int u, v, w;
cin >> u >> v >> w;
adj[u].push_back( { v, w } );
adj[v].push_back( { u, w } );
}
for ( int i = 1; i <= n; i++ ) {
dist[i] = 1e12;
pr[i] = i;
size[i] = 1;
}
int k;
cin >> k;
set < pair < int, int > > q;
for ( int i = 1; i <= k; i++ ) {
int x;
cin >> x;
q.insert( { 0, x } );
dist[x] = 0;
}
while ( !q.empty() ) {
int v = q.begin()->se;
q.erase( q.begin() );
for ( auto pr: adj[v] ) {
int u = pr.fi, w = pr.se;
if ( dist[u] > dist[v] + w ) {
q.erase( { dist[u], u } );
dist[u] = dist[v] + w;
q.insert( { dist[u], u } );
}
}
}
int qr;
cin >> qr;
for ( int i = 1; i <= qr; i++ ) {
int x, y;
cin >> x >> y;
st[x].insert(i);
st[y].insert(i);
}
vector < pair < int, int > > vc;
for ( int i = 1; i <= n; i++ ) {
vc.push_back( { dist[i], i } );
}
sort( vc.rbegin(), vc.rend() );
for ( int i = 0; i < n; i++ ) {
int x = vc[i].se;
used[x] = 1;
// cout << x << endl;
for ( auto pr: adj[x] ) {
int u = pr.fi;
if ( used[u] ) {
merge( x, u, dist[x] );
}
}
}
for ( int i = 1; i <= qr; i++ ) {
cout << ans[i] << '\n';
}
}