Submission #1084296

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084296		kokoue	Birthday gift (IZhO18_treearray)	C++14	12 / 100	4051 ms	11600 KiB

treearray

#include<bits/stdc++.h>
#define maxn 100010
#define f first
#define s second
using namespace std;
int n,m,q;
vector<int> edges[maxn];
int st[25][maxn];
int timer=0;
int tin[maxn],tout[maxn],depth[maxn];
int seq[maxn];
int tree[4*maxn];
void dfs(int start,int par)
{
    st[0][start]=par;
    tin[start]=timer++;
    depth[start]=depth[par]+1;
    for(auto e:edges[start])
    {
        if(e!=par)
        {
            dfs(e,start);
        }
    }
    tout[start]=timer++;
}
bool is_ancestor(int u,int v)
{
    if(tin[u]<tin[v] && tout[u]>tout[v]) return true;
    return false;
}
int lca(int u,int v)
{
    if(u==v) return u;
    if(is_ancestor(u,v)) return u;
    if(is_ancestor(v,u)) return v;
    for(int i=24;i>=0;i--)
    {
        if(!is_ancestor(st[i][u],v))
        {
            u=st[i][u];
        }
    }
    u=st[0][u];
    return u;
}
void build(int node=1,int l=1,int r=m)
{
    if(l==r)
    {
        tree[node]=seq[l];
        return;
    }
    int mid=(l+r)/2;
    int left=node<<1,right=left+1;
    build(left,l,mid);
    build(right,mid+1,r);
    tree[node]=lca(tree[left],tree[right]);
}
void update(int idx,int val,int node=1,int l=1,int r=m)
{
    if(idx<l || r<idx) return;
    if(l==r)
    {
        tree[node]=val;
        return;
    }
    int mid=(l+r)/2;
    int left=node<<1,right=left+1;
    update(idx,val,left,l,mid);
    update(idx,val,right,mid+1,r);
    tree[node]=lca(tree[left],tree[right]);
}
int query(int ql,int qr,int node=1,int l=1,int r=m)
{
    if(qr<l || r<ql) return 0;
    if(ql<=l && r<=qr) return tree[node];
    int mid=(l+r)/2;
    int left=node<<1,right=left+1;
    int ans=query(ql,qr,left,l,mid);
    int rans=query(ql,qr,right,mid+1,r);
    if(ans==0) return rans;
    if(rans==0) return ans;
    return lca(ans,rans);
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin>>n>>m>>q;
    for(int i=0;i<n-1;i++)
    {
        int a,b;
        cin>>a>>b;
        edges[a].push_back(b);
        edges[b].push_back(a);
    }
    dfs(1,1);
    for(int i=1;i<25;i++)
    {
        for(int j=1;j<=n;j++)
        {
            st[i][j]=st[i-1][st[i-1][j]];
        }
    }
    for(int i=1;i<=m;i++)
    {
        cin>>seq[i];
    }
    build();
    //printf("done building\n");
    //printf("query %d\n",query(1,4));
   // printf("query %d\n",query(2,2));
    for(int i=0;i<q;i++)
    {
        int t;
        cin>>t;
        if(t==1)
        {
            int idx,val;
            cin>>idx>>val;
            update(idx,val);
            //printf("done update\n");
        }
        if(t==2)
        {
            int l,r,hole;
            cin>>l>>r>>hole;
           // printf("query %d\n",query(2,2));
            int idxl=-1,idxr=-1;
            for(int j=l;j<=r;j++)
            {
                for(int h=j;h<=r;h++)
                {
                    if(query(j,h)==hole)
                    {
                        if(idxl==-1) {idxl=j;idxr=h;continue;}
                        if(idxr-idxl<h-j) {idxl=j;idxr=h;}
                    }
                }
            }
            cout<<idxl<<" "<<idxr<<"\n";
        }
    }
}
/*
5 4 4
1 2
3 1
3 4
5 3
4 5 2 3
2 1 3 1
1 3 5
2 3 4 5
2 1 3 1
*/

• Subtask 1: 12 / 12
• Subtask 2: 0 / 18
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44