Submission #1083277

#	Time	Username	Problem	Language	Result	Execution time	Memory
1083277		rayan_bd	Regions (IOI09_regions)	C++17	0 / 100	1254 ms	131072 KiB

regions

#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define ll long long

const int mxN = 2e5 + 5000;

vector<ll> adj[mxN];
ll hd[mxN];
map<ll,vector<ll>> same;
vector<map<ll,ll>> seg(mxN*4);
ll st[mxN],en[mxN],lt[mxN],tin=-1;

void answer(ll ans){
	cout.flush()<<ans<<'\n';
    cout.flush();
}

void build(ll node,ll start,ll end){
	if(start==end){
		seg[node][hd[lt[start]]]=1;
		return;
	}
	ll mid=start+(end-start)/2;
	build(node*2+1,start,mid);
	build(node*2+2,mid+1,end);
	for(auto it:seg[node*2+1]) seg[node][it.first]=it.second;
	for(auto it:seg[node*2+2]) seg[node][it.first]+=it.second;
}

void dfs(ll u=1,ll par=-1){
	st[u]=++tin;
	lt[tin]=u;
	for(auto it:adj[u]){
		if(it^par){
			dfs(it,u);
		}
	}
	en[u]=tin;
}

ll qry(ll node,ll start,ll end,ll l,ll r,ll x){
	if(start>r||end<l) return 0;
	if(start>=l&&end<=r) return seg[node][x];
	ll mid=start+(end-start)/2;
	return qry(node*2+1,start,mid,l,r,x)+qry(node*2+2,mid+1,end,l,r,x);
}

void Solve(){
	ll n,k,q,r1,r2,ans=0,super;cin>>n>>k>>q;

	cin>>hd[1];
	same[hd[1]].pb(1);

	for(ll i=2;i<=n;++i){
		cin>>super>>hd[i];
		adj[i].pb(super);
		adj[super].pb(i);
		same[hd[i]].pb(i);
	}

	dfs();
	build(0,0,tin);
	
	while(q--){
		cin>>r1>>r2;
		ans=0;
		for(auto it:same[hd[r1]]){
			ans+=qry(0,0,tin,st[it],en[it],r2);
		}
		answer(ans);
	}
}

void testing(){
	#ifndef ONLINE_JUDGE
    freopen("input.in","r",stdin);
    freopen("output.out","w",stdout);
    #endif
}

int main() {
    
	//testing();

    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    
    Solve();

    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'void testing()':
regions.cpp:79:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |     freopen("input.in","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
regions.cpp:80:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |     freopen("output.out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 85