Submission #827873

#	Time	Username	Problem	Language	Result	Execution time	Memory
827873		CSQ31	Cat Exercise (JOI23_ho_t4)	C++17	21 / 100	2075 ms	35428 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
const int MAXN = 2e5+5;
vector<int>adj[MAXN];
vector<pii>g[MAXN];
int p[MAXN],rp[MAXN],t[4*MAXN],lazy[4*MAXN];
void pushdown(int v){
	if(!lazy[v])return;
	t[2*v] = lazy[2*v] = t[2*v+1] = lazy[2*v+1] = lazy[v];
	lazy[v] = 0;
}
void upd(int v,int l,int r,int tl,int tr,int val){
	if(l>r)return;
	if(l==tl && r==tr){
		t[v] = lazy[v] = val;
		return;
	}
	pushdown(v);
	int tm = (tl+tr)/2;
	upd(2*v,l,min(r,tm),tl,tm,val);
	upd(2*v+1,max(l,tm+1),r,tm+1,tr,val);
	t[v] = max(t[2*v],t[2*v+1]);
}
int query(int v,int l,int r,int tl,int tr){
	if(l>r)return -1;
	if(l==tl && r==tr)return t[v];
	pushdown(v);
	int tm = (tl+tr)/2;
	return max(
	query(2*v,l,min(r,tm),tl,tm),
	query(2*v+1,max(l,tm+1),r,tm+1,tr));
}
int dep[MAXN],par[MAXN],ded[MAXN];
void dfs(int v){
	for(int x:adj[v]){
		if(x != par[v]){
			par[x] = v;
			dep[x] = dep[v]+1;
			dfs(x);
		}
	}
}
int dfs2(int v){
	int mx = 0;
	for(pii x:g[v]){
		mx = max(mx,dfs2(x.fi)+x.se);
	}
	return mx;
}

int find(int v,int u){
	int res = p[v];
	for(int x:adj[v]){
		if(x==u || ded[x])continue;
		res = max(res,find(x,v));
	}
	return res;
}
void solve(int v,int p){
	v = rp[find(v,-1)];
	ded[v] = 1;
	if(p)g[p].pb({v,abs(dep[v]-dep[p])});
	for(int x:adj[v]){
		if(ded[x])continue;
		solve(x,v);
	}
}

int main()
{
	owo
	int n;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>p[i];
		rp[p[i]] = i;
	}
	for(int i=1;i<n;i++){
		int v,u;
		cin>>v>>u;
		adj[v].pb(u);
		adj[u].pb(v);
	}
	dfs(rp[n]);
	solve(1,0);
	cout<<dfs2(rp[n]);
	
	
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26