Submission #1184387

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184387		son2008	Ball Machine (BOI13_ballmachine)	C++20	100 / 100	162 ms	34936 KiB

ballmachine

#include<bits/stdc++.h>
using namespace std;
#define task "task"
#define ii pair<int,int>
#define fi first
#define se second
//#define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int,ii>
#define iiii pair<ii,ii>
//#define base 29
#define eps 1e-8
int dx[]= {0LL,0LL,1,-1,1,1,-1,-1};
int dy[]= {1,-1,0LL,0LL,1,-1,1,-1};
const int maxn=4e5+1;
const int mod=1e9+7;
int goc,id[maxn],pos[maxn],timer,mn[maxn],P[maxn][lg2+1],n,q;
vector<int>a[maxn];
bool cmp(int x,int y)
{
    return mn[x]<mn[y];
}
void dfs(int u)
{
    mn[u]=u;
    for(int v:a[u])
    {
        dfs(v);
        P[v][0]=u;
        mn[u]=min(mn[v],mn[u]);
    }
    sort(a[u].begin(),a[u].end(),cmp);
}
void gan(int u)
{
    for(int v:a[u])
    {
        gan(v);
    }
    id[u]=++timer;
    pos[timer]=u;
}
struct FEN
{
    int n;
    vector<int>bit;
    FEN(){};
    FEN(int _n):bit(n+1,0),n(_n+1)
    {
    };
    int get(int r) {
        int ret = 0;
        for (; r >= 0; r = (r & (r + 1)) - 1)
            ret += bit[r];
        return ret;
    }

    int get(int l, int r) {
        return get(r) - get(l - 1);
    }

    void update(int idx, int delta) {
        for (; idx < n; idx = idx | (idx + 1))
            bit[idx] += delta;
    }
    void updateRange(int l,int r,int val)
    {
        update(l,val);
        update(r+1,-val);
    }
}bit;
void init()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        int p;
        cin>>p;
        if(!p)goc=i;
        else a[p].push_back(i);
    }
    dfs(goc);
    gan(goc);
    for(int j=1;j<=lg2;j++)
    {
        for(int i=1;i<=n;i++)
        {
            P[i][j]=P[P[i][j-1]][j-1];
        }
    }
    bit=FEN(n+2);
    for(int i=1;i<=n;i++)bit.update(i,-1);
    while(q--)
    {
        int t;
        cin>>t;
        if(t==1)
        {
            int k;
            cin>>k;
            int ans=0;
            for(int i=1;i<=k;i++)
            {
                int l=0,r=n;
                while(l<=r)
                {
                    int mid=(l+r)/2;
                    if(bit.get(mid)<0)
                    {
                        r=mid-1;
                        ans=mid;
                    }
                    else l=mid+1;
                }
               // cout<<ans<<" ";
                bit.update(ans,1);
            }
          //  cout<<ans<<'\n';
            cout<<pos[ans]<<'\n';
        }
        else
        {
            int u;
            cin>>u;
            int ans=0;
            for(int j=lg2;j>=0;j--)
            {
                if(P[u][j]&&bit.get(id[P[u][j]])==bit.get(id[P[u][j]]-1))
                {
                    ans+=(1<<j);
                    u=P[u][j];
                }
            }
            bit.update(id[u],-1);
            cout<<ans<<'\n';
        }
    }
}
void process()
{
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    int t=1;
   // cin>>t;
    while(t--)
    {
    init();
    process();
    cout<<'\n';
    }
    cerr <<endl<< "TIME : " << clock() * 0.001 << "s" << endl ;
}

Compilation message (stderr)

ballmachine.cpp: In function 'int main()':
ballmachine.cpp:152:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  152 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
ballmachine.cpp:153:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  153 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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