Submission #976409

#	Time	Username	Problem	Language	Result	Execution time	Memory
976409		modwwe	Cat Exercise (JOI23_ho_t4)	C++17	54 / 100	137 ms	39968 KiB

Main

#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,sse,sse2")
#include<bits/stdc++.h>
//#define int long long
//#define ll long long
#define down cout<<'\n';
#define NHP     ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe  int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define checktime   cerr << (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
using namespace std;
void ngha();
const int mod2=1e9+7;
const int  mod1=998244353;
struct ib
{
    int a;
    int b;
};
struct icd
{
    int a,b;
};
struct ic
{
    int a,b,c;
};
struct id
{
    int a,b,c,d;
};
struct ie
{
    int a,b,c, d,e;

};
int n,m,s1,s2,s4,s3,sf,k,r,mid,s5,s6,mx,s7,s8,s9,mx2,res,dem2=0,dem=0,l;
int  i,s10,s12;
int el=29;
main()
{
//#ifndef ONLINE_JUDGE
    /// fin(task),fou(task);
//#endif
    NHP
//modwwe
    //  cin>>res;
    ngha();

}
vector<int>v[200001];
int dp[200001];
ic dsu[200001];
int st[18][200001];
int a[200001];
int d[200001];
void reset(int x)
{
    dsu[x]= {1,x,x};
}
int get(int x)
{
    if(x!=dsu[x].b)dsu[x].b=get(dsu[x].b);
    return dsu[x].b;
}
void noi(int x,int y)
{x=get(x);
y=get(y);
    if(x==y) return;
    if(dsu[x].a<dsu[y].a) swap(x,y);
    dsu[x].a+=dsu[y].a;
    dsu[y].b=x;
    dsu[x].c=min(dsu[x].c,dsu[y].c);
}
void dfs(int x,int y)
{
    st[0][x]=y;
    d[x]=d[y]+1;
    for(auto f:v[x])
    {
        if(f!=y)
        {
            dfs(f,x);
        }
    }
}
int lca(int x,int y)
{
    if(d[x]>d[y])swap(x,y);
     int ss=d[y]-d[x];
    for(int i=17;i>=0;--i)
        if(bit(ss,i))
    {
         y=st[i][y];
    }

    if(x==y) return x;
     for(int i=17;i>=0;--i)
     {
         if(st[i][y]!=st[i][x])
         {
             y=st[i][y];
             x=st[i][x];
         }
     }
     return st[0][x];
}
bool cmp(ib a,ib b){
 return a.a<b.a;
  }
/// lca(x,y)+lca(y,z)>=lca(x,z)
void ngha()
{
    cin>>n;
    for(int i=1; i<=n; i++)
        cin>>a[i],reset(i);
    for(int i=1; i<n; i++)
    {
        cin>>l>>r;
        v[n-a[l]+1].pb(n-a[r]+1);
        v[n-a[r]+1].pb(n-a[l]+1);
    }
    dfs(1,0);
    for(int i=1; i<18; i++)
        for(int j=1; j<=n; j++)
            st[i][j]=st[i-1][st[i-1][j]];
    for(int i=n; i>=1; i--)
    { ///cout<<i,down
        for(auto x:v[i])
        {
            if(x<i) continue;
            s2=get(x);
s2=dsu[s2].c;
        s3=lca(s2,i);
        noi(s2,i);
        dp[i]=max(dp[i],dp[s2]+d[i]+d[s2]-2*d[s3]);
        }
               }
    //cout<<lca(1,2);

    s2=0;
    for(int  i=1;i<=n;i++)
 s2=max(s2,dp[i]);
 cout<<s2;
}

Compilation message (stderr)

Main.cpp:45:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   45 | main()
      | ^~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 10 / 10
• Subtask 5: 0 / 20
• Subtask 6: 23 / 23
• Subtask 7: 0 / 26