Submission #493486

#	Time	Username	Problem	Language	Result	Execution time	Memory
493486		_Monkey_	Ball Machine (BOI13_ballmachine)	C++17	100 / 100	141 ms	21164 KiB

ballmachine

#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define el '\n'
const int maxn=1e5+1,oo=1e9;
void amin(int &x,int y){ if(x>y) x=y;}
void amax(int &x,int y){ if(x<y) x=y;}

int n,m,opt,o,cnt,k,u,val,ans;
vector<vector<int>> con,far;
vector<int> cha,minn,ut,reut,st;
vector<bool> ok;

// trade 1
bool check(int x,int y){
    return minn[x]<minn[y];
}
int prepare(int z){
    minn[z]=z;
    for(int &e:con[z]) amin(minn[z],prepare(e));
    return minn[z];
}
void dfs(int z){
    for(int &e:con[z]) dfs(e);
    cnt++;
    ut[z]=cnt;
    reut[cnt]=z;
    return;
}
void pre_up(int id,int l,int r){
    if(r<u || l>u) return;
    if(l==r){
        st[id]+=val;
        return;
    }
    int mid=(l+r)/2;
    pre_up(id*2,l,mid);
    pre_up(id*2+1,mid+1,r);
    st[id]=st[id*2]+st[id*2+1];
    return;
}
void up(int id,int v){
    u=id;
    val=v;
    return pre_up(1,1,n);
}
void pre_get(int id,int l,int r){
    if(l==r){
        ans=l;
        ok[l]=1;
        up(l,1);
        return;
    }
    int mid=(l+r)/2;
    if(mid-l+1==st[id*2]) pre_get(id*2+1,mid+1,r);
    else pre_get(id*2,l,mid);
}
void get(){
    return pre_get(1,1,n);
}

// trade 2

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);

    cin >> n >> m;
    con.resize(n+1);
    cha.resize(n+1);
    minn.resize(n+1);
    ut.resize(n+1);
    reut.resize(n+1);
    st.resize(n*4+1);
    ok.resize(n+1);
    far.resize(18,vector<int> (n+1));

    for(int i=1;i<=n;++i){
        cin >> cha[i];
        con[ cha[i] ].push_back(i);
    }
    opt=con[0][0];
    prepare(opt);
    for(int i=1;i<=n;++i) sort(con[i].begin(),con[i].end(),check);
    dfs(opt);

    for(int i=1;i<=n;++i) far[0][ut[i]]=ut[cha[i]];
    for(int i=1;i<18;++i){
        for(int j=1;j<=n;++j){
            far[i][j]=far[i-1][ far[i-1][j] ];
        }
    }
    while(m--){
        cin >> o >> k;
        if(o==1){
            for(int i=0;i<k;++i) get();
            cout << reut[ans] << el;
        } else {
            cnt=0;
            k=ut[k];
            for(int i=17;i>=0;--i) if(ok[ far[i][k] ]){
                cnt+=(1<<i);
                k=far[i][k];
            }
            up(k,-1);
            ok[k]=0;
            cout << cnt << el;
        }
    }
    return 0;
}

• Subtask 1: 25 / 25
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40
• Subtask 4: 5 / 5