Submission #830139

#	Time	Username	Problem	Language	Result	Execution time	Memory
830139		MohamedAhmed04	Designated Cities (JOI19_designated_cities)	C++14	100 / 100	1632 ms	52684 KiB

designated_cities

#include <bits/stdc++.h>
 
using namespace std ;
 
const int MAX = 2e5 + 10 ;
 
int arr[MAX] ;
int n , q ;
 
vector< vector< pair<int , int> > >adj(MAX) ;
 
long long ans[MAX] ;
 
int mark[MAX] ;
int sz[MAX] ;
int cursrc , cursz ;
long long curcost ;
 
pair<long long , int>tree[4 * MAX] ;
long long lazy[4 * MAX] ;

int id[MAX] ;
long long val3[MAX] ;
 
void build(int node , int l , int r)
{
	lazy[node] = 0 ;
	if(l == r)
	{
		tree[node] = {val3[id[l]] , id[l]} ;
		return ;
	}
	int mid = (l + r) >> 1 ;
	build(node << 1 , l , mid) ;
	build(node << 1 | 1 , mid+1 , r) ;
	tree[node] = max(tree[node << 1] , tree[node << 1 | 1]) ;
}
 
void prop(int node , int l , int r)
{
	tree[node].first += lazy[node] ;
	if(l != r)
	{
		lazy[node << 1] += lazy[node] ;
		lazy[node << 1 | 1] += lazy[node] ;
	}
	lazy[node] = 0 ;
}
 
void update(int node , int l , int r , int from , int to , int val)
{
	if(lazy[node])
		prop(node , l , r) ;
	if(from > r || to < l)
		return ;
	if(l >= from && r <= to)
	{
		lazy[node] += val ;
		prop(node , l , r) ;
		return ;
	}
	int mid = (l + r) >> 1 ;
	update(node << 1 , l , mid , from , to , val) ;
	update(node << 1 | 1 , mid+1 , r , from , to , val) ;
	tree[node] = max(tree[node << 1] , tree[node << 1 | 1]) ;
}
 
pair<long long , int>query(int node , int l , int r , int from , int to)
{
	if(lazy[node])
		prop(node , l , r) ;
	if(from > r || to < l || from > to)
		return {-1e18 , -1e9} ;
	if(l >= from && r <= to)
		return tree[node] ;
	int mid = (l + r) >> 1 ;
	pair<long long , int>a = query(node << 1 , l , mid , from , to) ;
	pair<long long , int>b = query(node << 1 | 1 , mid+1 , r , from , to) ;
	return max(a , b) ;
}
 
void dfs_pre(int node , int par)
{
	sz[node] = 1 ;
	for(auto &childd : adj[node])
	{
		int child = childd.first ;
		if(child == par || mark[child])
			continue ;
		dfs_pre(child , node) ;
		sz[node] += sz[child] ;
	}
}
 
int FindCentroid(int node , int par)
{
	for(auto &childd : adj[node])
	{
		int child = childd.first ;
		if(child == par || mark[child])
			continue ;
		if(sz[child] > cursz / 2)
			return FindCentroid(child , node) ;
	}
	return node ;
}
 
int val[MAX] ;
int in[MAX] , out[MAX] ;
int tim = 0 ;
int sub[MAX] , P[MAX] , erased[MAX] , edgcost[MAX] ;
long long sum[MAX] , Max[MAX] ;
 
void dfs(int node , int par)
{
	in[node] = ++tim , id[tim] = node , P[node] = par ;
	curcost += val[node] , erased[node] = 0 ;
	sum[node] = Max[node] = val[node] ;
	for(auto &childd : adj[node])
	{
		int child = childd.first , w = childd.second ;
		if(child == par)
			edgcost[node] = w ;
		if(child == par || mark[child])
			continue ;
		val[child] = w , val3[child] = val3[node] + w ;
		if(in[node] == 1) //centroid
			sub[child] = child ;
		else
			sub[child] = sub[node] ;
		dfs(child , node) ;
		sum[node] += sum[child] ;
		Max[node] = max(Max[node] , Max[child] + val[node]) ;
	}
	out[node] = tim ;
}
 
void Erase(int node)
{
	while((!erased[node]) && node)
	{
		erased[node] = 1 ;
		update(1 , 1 , cursz , in[node] , out[node] , -1 * val[node]) ;
		node = P[node] ;
	}
}
 
void solve(int src , long long cost)
{
	tim = 0 ;
	cursrc = src , curcost = cost ;
	dfs_pre(src , 0) ;
	cursz = sz[src] ;
	int centroid = FindCentroid(src , -1) ;
	val[centroid] = val3[centroid] = 0 ;
	dfs(centroid , 0) ;
	build(1 , 1 , cursz) ;
	ans[1] = min(ans[1] , curcost) ;
	long long Max1 = 0 , Max2 = 0 ;
	for(auto &childd : adj[centroid])
	{
		int child = childd.first , w = childd.second ;
		if(mark[child])
			continue ;
		if(Max[child] > Max1)
			Max2 = Max1 , Max1 = Max[child] ;
		else if(Max[child] > Max2)
			Max2 = Max[child] ;
	}
	bool flag = true ;
	int prv ;
	for(int i = 1 ; i <= cursz ; ++i)
	{
		pair<long long , int>p = query(1 , 1 , cursz , 1 , cursz) ;
		if((!p.first))
		{
			ans[i] = min({ans[i] , curcost , ans[i-1]}) ;
			break ;
		}
		int node = p.second ;
		if(i > 1)
			flag &= (sub[node] == sub[prv]) ;
		curcost -= p.first , Erase(node) ;
		if(!flag)
			ans[i] = min(ans[i] , curcost) ;
		else if(i > 1)
			ans[i] = min(ans[i] , curcost + p.first - Max2) ;
		prv = node ;
	}
	mark[centroid] = 1 ;
	for(auto &childd : adj[centroid])
	{
		int child = childd.first , w = childd.second ;
		if(mark[child])
			continue ;
		solve(child , cost + sum[centroid] - sum[child] + edgcost[child]) ;
	}
}
 
int main()
{
	ios_base::sync_with_stdio(0) ;
	cin.tie(0) ;
	cin>>n ;
	for(int i = 0 ; i < n-1 ; ++i)
	{
		int x , y , c , d ;
		cin>>x>>y>>c>>d ;
		adj[x].emplace_back(y , c) ;
		adj[y].emplace_back(x , d) ;
	}
	for(int i = 0 ; i <= n ; ++i)
		ans[i] = 1e18 ;
	solve(1 , 0) ;
	for(int i = 1 ; i <= n ; ++i)
		ans[i] = min(ans[i] , ans[i-1]) ;
	cin>>q ;
	while(q--)
	{
		int x ;
		cin>>x ;
		cout<<ans[x]<<"\n" ;
	} 
	return 0 ;
}	

Compilation message (stderr)

designated_cities.cpp: In function 'void solve(int, long long int)':
designated_cities.cpp:162:30: warning: unused variable 'w' [-Wunused-variable]
  162 |   int child = childd.first , w = childd.second ;
      |                              ^
designated_cities.cpp:193:30: warning: unused variable 'w' [-Wunused-variable]
  193 |   int child = childd.first , w = childd.second ;
      |                              ^

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 9 / 9
• Subtask 4: 17 / 17
• Subtask 5: 17 / 17
• Subtask 6: 44 / 44