Submission #964902

#	Time	Username	Problem	Language	Result	Execution time	Memory
964902		PieArmy	Regions (IOI09_regions)	C++17	44 / 100	2217 ms	131072 KiB

regions

typedef long long ll;
#include <bits/stdc++.h>
#define pb push_back
#define int ll
using namespace std;

int n,sq,R,Q;
int pre[25001][450],pre2[450][25001],say[25001],fazlapos[25001];
vector<int>renk,bas,son;
vector<int>child[200001],var[25001],sirali[25001];

int cal(int a,int b){
    if(say[b]==0||say[a]==0){
        return 0;
    }
    if(say[b]>sq){
        return pre[a][fazlapos[b]];
    }
    if(say[a]>sq){
        return pre2[fazlapos[a]][b];
    }
    int sta[say[a]];
    int tavan=-1;
    int apos=0;
    int ans=0;
    for(int i=0;i<say[b];i++){
        while(tavan!=-1&&son[sta[tavan]]<bas[var[b][i]]){
            tavan--;
        }
        while(apos<say[a]&&bas[sirali[a][apos]]<=bas[var[b][i]]){
            if(son[sirali[a][apos]]>=bas[var[b][i]]){
                tavan++;
                sta[tavan]=sirali[a][apos];
            }
            apos++;
        }
        ans+=tavan+1;
    }
    return ans;
}

void code(){
    cin>>n>>R>>Q;
    renk.resize(n+1);
    bas.resize(n+1);
    son.resize(n+1);
    sq=sqrt(n);
    cin>>renk[1];
    int time=0;
    say[renk[1]]++;
    for(int &x:fazlapos)
        x=-1;
    for(int i=2;i<=n;i++){
        int par;cin>>par;
        child[par].pb(i);
        cin>>renk[i];
        if(say[renk[i]]==sq){
            fazlapos[renk[i]]=time;
            time++;
        }
        say[renk[i]]++;
    }
    function<int(int,int)>f=[&](int pos,int tur)->int{
        int res=0;
        for(int x:child[pos]){
            res+=f(x,tur);
        }
        if(renk[pos]==tur)return res+1;
        pre[renk[pos]][fazlapos[tur]]+=res;
        return res;
    };
    function<void(int,int,int)>f2=[&](int pos,int tur,int sum)->void{
        if(renk[pos]!=tur)pre2[fazlapos[tur]][renk[pos]]+=sum;
        else sum++;
        for(int x:child[pos]){
            f2(x,tur,sum);
        }
    };
    for(int i=1;i<=R;i++){
        if(fazlapos[i]==-1)continue;
        f(1,i);
        f2(1,i,0);
    }
    time=1;
    function<void(int)>turla=[&](int pos)->void{
        if(say[renk[pos]]<=sq){
            bas[pos]=time;
            var[renk[pos]].pb(pos);
            sirali[renk[pos]].pb(pos);
        }
        time++;
        for(int x:child[pos]){
            turla(x);
        }
        son[pos]=time-1;
    };
    turla(1);
    for(int i=1;i<=R;i++){
        if(say[i]>sq)continue;
        sort(sirali[i].begin(),sirali[i].end(),[&](const int &x,const int &y){
            if(bas[x]==bas[y]){
                return son[x]<son[y];
            }
            return bas[x]<bas[y];
        });
    }
    while(Q--){
        int a,b;cin>>a>>b;
        cout<<cal(a,b)<<endl;
    }
}

int32_t main(){
    bool usaco=0;if(usaco){freopen(".in","r",stdin);freopen(".out","w",stdout);}
    int t=1;
    if(!t)cin>>t;
    while(t--){code();cout<<endl;}
    return 0;
}

Compilation message (stderr)

regions.cpp: In function 'int32_t main()':
regions.cpp:114:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |     bool usaco=0;if(usaco){freopen(".in","r",stdin);freopen(".out","w",stdout);}
      |                            ~~~~~~~^~~~~~~~~~~~~~~~~
regions.cpp:114:60: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |     bool usaco=0;if(usaco){freopen(".in","r",stdin);freopen(".out","w",stdout);}
      |                                                     ~~~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 15
• Subtask 2: 30 / 85