Submission #1142404

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142404		ackhava	Cat Exercise (JOI23_ho_t4)	C++20	100 / 100	369 ms	82228 KiB

Main

#include <bits/stdc++.h>
#define int long long
#define REP(v, i, j) for (int v = i; v != j; v++)
#define FORI(v) for (auto i : v)
#define FORJ(v) for (auto j : v)

#define OUT(v, a) \
    FORI(v)       \
    cout << i << a;
#define OUTS(v, a, b)      \
    cout << v.size() << a; \
    OUT(v, b)
#define in(a, n) \
    REP(i, 0, n) \
    cin >> a[i];

#define SORT(v) sort(begin(v), end(v))
#define REV(v) reverse(begin(v), end(v))
#define MEMSET(m) memset(m, -1, sizeof m)

#define pb push_back
#define fi first
#define se second

#define detachIO                      \
    ios_base::sync_with_stdio(false); \
    cin.tie(0);                       \
    cout.tie(0);
    
using namespace std;

template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
bool operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y) {
    if(__x.size() != __y.size()) return false;
    return std::equal(__x.begin(), __x.end(), __y.begin());
}


typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<pii, pii> piiii;

const int MOD = 1e9+7;

struct modint {
    long long val;

    modint() = default;
    modint(int _val): val(_val){}
    modint operator+(modint b){ return ((this->val + b.val)%MOD); }
    modint operator-(modint b){ return ((MOD + this->val - b.val)%MOD); }
    modint operator*(modint b){ return ((this->val * b.val)%MOD); }
    modint operator^(int a){
        if(a==0)return 1;
        if(a==1)return *this;
        return (((*this)*(*this))^(a>>1))*((*this)^(a&1)); 
    }
};

modint invert(modint a){
    return a^(MOD-2);
}

modint operator/(modint a, modint b){
    return a*invert(b);
}

vector<int> add[200100];
vector<int> adj[200100];

int p[200100];
int m[200100];

struct dsu{
    vector<int> vec;
    vector<int> dat;
    dsu(int n){
        vec.clear();
        dat.clear();
        vec.resize(n+20,-1);
        dat.resize(n+20,-1);
        REP(i,0,dat.size())dat[i]=i;
    }

    int leader(int n){return vec[n]<0?n:vec[n]=leader(vec[n]);}
    void merge(int n,int m){n=leader(n),m=leader(m);if(vec[n]>vec[m])swap(n,m);
    vec[n]+=vec[m];vec[m]=n;
    if(dat[n]<dat[m])dat[n]=dat[m];}
};

int lift[200100][30];
int d[200100];

void dfs(int node, int parent, int dep){
    d[node]=dep;
    lift[node][0]=parent;
    FORI(adj[node]){
        if(i!=parent)dfs(i,node,dep+1);
    }
}

int dist(int u, int v){
    int x=u,y=v;
    int ans=0;
    REP(ix,0,30){    
        auto i=30-1-ix;
        if(d[lift[u][i]]>d[v])u=lift[u][i],ans+=(1<<i);
    }
    swap(u,v);
    REP(ix,0,30){    
        auto i=30-1-ix;
        if(d[lift[u][i]]>d[v])u=lift[u][i],ans+=(1<<i);
    }
    while(d[u]>d[v])u=lift[u][0],ans++;
    swap(u,v);
    while(d[u]>d[v])u=lift[u][0],ans++;

    REP(ix,0,30){    
        auto i=30-1-ix;
        if(lift[u][i]!=lift[v][i])u=lift[u][i],v=lift[v][i],ans+=(1<<i),ans+=(1<<i);
    }
    while(u!=v)u=lift[u][0],v=lift[v][0],ans+=2;
    // cerr<<x<<' '<<y<<" -> "<<ans<<endl;
    return ans;
}

signed main(){
    detachIO;
    int n;cin>>n;
    REP(i,1,n+1){
        cin>>p[i];
    }
    REP(i,1,n){
        int a,b;cin>>a>>b;
        a=p[a];
        b=p[b];
        if(a<b)swap(a,b);
        add[a].pb(b);
        adj[a].pb(b);
        adj[b].pb(a);
    }
    dfs(1,-1,0);
    lift[1][0]=1;
    REP(j,1,30)REP(i,1,n+1)lift[i][j]=lift[lift[i][j-1]][j-1];
    REP(i,1,n+1)adj[i].clear();
    dsu d(n+20);
    REP(i,1,n+1){
        adj[i]=add[i];
        FORJ(adj[i])adj[j].pb(i);
        FORJ(adj[i]){
            m[i]=max(m[i],m[d.dat[d.leader(j)]]+dist(i,d.dat[d.leader(j)]));
            d.merge(i,j);
        }
        // cerr<<m[i]<<'\n';
    }
    cout<<m[n];
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 23 / 23
• Subtask 7: 26 / 26