Submission #681992

#	Time	Username	Problem	Language	Result	Execution time	Memory
681992		LeVanThuc	Regions (IOI09_regions)	C++17	100 / 100	4510 ms	35508 KiB

regions

#include<bits/stdc++.h>
using namespace std;
#define ll int
#define fi first
#define se second
#define p(x,y) pair<ll,ll>(x,y)
#define BIT(i,x) ((x>>i)&1)
#define MASK(x) (1<<x)
#define ld long double
#define __builtin_popcount __builtin_popcountll
#define pll pair<ll,ll>
template<class T1,class T2>
bool maximize(T1 &x,const T2 &y)
{
    if(x<y)
    {
        x=y;
        return 1;
    }
    return 0;
}
template<class T1,class T2>
bool minimize(T1 &x,const T2 &y)
{
    if(x>y)
    {
        x=y;
        return 1;
    }
    return 0;
}
void online()
{
    std::ios_base::sync_with_stdio(0);
    cin.tie(0);
#ifndef ONLINE_JUDGE
    freopen("input.inp", "r", stdin);
    freopen("output.out","w", stdout);
#else
#endif
}
static const ll N=2e5+10,Block=450;
ll in[N],out[N],Psol[Block+10][N],Prep[N],e[N],n,r,q,cnt,Pcnt;
vector<ll> gr[N],Reg[N],Member[N];
void dfs(ll u)
{
    in[u]=++cnt;
    Member[e[u]].push_back(in[u]);
    for(auto v:gr[u]) dfs(v);;
    out[u]=cnt;
}
void dfs1(ll u,ll head,ll crr)
{
    if(e[u]==head) crr++;
    Psol[Pcnt][e[u]]+=crr;
    for(auto v:gr[u]) dfs1(v,head,crr);
}
int main()
{
//    online();
    cin>>n>>r>>q;
    cin>>e[1];
    Reg[e[1]].push_back(1);
    for(int i=2;i<=n;i++)
    {
        ll v,c;
        cin>>v>>c;
        gr[v].push_back(i);
        e[i]=c;
        Reg[c].push_back(i);
    }
    dfs(1);
    for(int i=1;i<=r;i++)
    {
        if(Reg[i].size()<Block) continue;
        Prep[i]=++Pcnt;
        dfs1(1,i,0);
    }
//    for(int i=1;i<=r;i++)
//    {
//        for(auto v:Member[i]) cout<<v<<' ';
//        cout<<'\n';
//    }
    while(q--)
    {
        ll a,b;
        cin>>a>>b;
        if(Prep[a]) cout<<Psol[Prep[a]][b]<<endl;
        else
        {
            ll res=0;
            for(auto v:Reg[a])
            {
                res+=lower_bound(Member[b].begin(),Member[b].end(),out[v]+1)-Member[b].begin();
                res-=lower_bound(Member[b].begin(),Member[b].end(),in[v]) -Member[b].begin();
            }
            cout<<res<<endl;
        }
    }
}

Compilation message (stderr)

regions.cpp: In function 'void online()':
regions.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("input.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
regions.cpp:38:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |     freopen("output.out","w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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