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답안 #493993

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
493993 2021-12-13T17:12:00 Z fcmalkcin Mergers (JOI19_mergers) C++17
0 / 100
 124 ms 54568 KB 
/*#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops, no-stack-protector")
#pragma GCC target("avx,avx2,fma")*/

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

#define ll  long long
#define pll pair<ll,ll>
#define ff first
#define ss second
#define pb push_back
#define endl "\n"
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

const ll maxn=5e5+20;
const ll mod=998244353  ;
const ll base=1e9+100;

/// you will be the best but now you just are trash
/// goal 5/7

ll anc[maxn][20];
ll par1[maxn];
ll a[maxn];
ll par[maxn];
vector<ll> gr[maxn];
vector<ll> adj[maxn];
ll cntnw=0;
ll f[maxn];
ll dep[maxn];
ll find_par(ll u)
{
    if (u==par[u]) return u;
    return par[u]=find_par(par[u]);
}
void dsu(ll x,ll y)
{
    x=find_par(x);
    y=find_par(y);
    if (x==y)
    {
        return ;
    }
    if (dep[x]<dep[y]) swap(x,y);
    par[x]=y;
}
void dfs(ll u,ll par)
{
    cntnw++;
    f[u]=cntnw;
    anc[u][0]=par;
    for (int i=1;i<20;i++) anc[u][i]=anc[anc[u][i-1]][i-1];
    par1[u]=par;
    for (auto to:adj[u])
    {
        if (to==par) continue;
        dep[to]=dep[u]+1;
        dfs(to,u);
    }
}
ll lca(ll x,ll y)
{
    if (dep[x]<dep[y]) swap(x,y);
    ll kc=dep[x]-dep[y];
    for (int i=19;i>=0;i--)
    {
        if (kc&(1ll<<i))
        {
            x=anc[x][i];
        }
    }
    if (x==y) return x;
    for (int i=19;i>=0;i--)
    {
        if (anc[x][i]!=anc[y][i])
        {
            x=anc[x][i];
            y=anc[y][i];
        }
    }
    return anc[x][0];
}
ll cnt[maxn];

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    if (fopen("t.inp", "r"))
    {
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n, k;
    cin>> n>> k;
    vector<pll> vt;
    for (int i=1;i<=n-1;i++)
    {
        ll x, y;
        cin>>x>> y;
        vt.pb(make_pair(x,y));
        adj[x].pb(y);
        adj[y].pb(x);
    }
    for (int i=1;i<=n;i++)
    {
        par[i]=i;
        cin>>a[i];
        gr[a[i]].pb(i);
    }
    dfs(1,0);
    for (int i=1;i<=n;i++)
    {
        for (auto to:adj[i])
        {
            if (a[to]==a[i]) dsu(to,i);
        }
    }
    for (int i=1;i<=k;i++)
    {
        set<pll> st;
        for (auto p:gr[i])
        {
            ll x=find_par(p);
            st.insert(make_pair(f[x],x));
         //   if (i==1) cout <<f[x]<<" "<<x<<" "<<p<<endl;
        }
        gr[i].clear();
        while (st.size()>=2)
        {
            auto p=(*st.begin());
            st.erase(st.begin());
            auto p1=(*st.begin());
            st.erase(st.begin());
            ll pos=p.ss;
            ll pos1=p1.ss;
            vector<ll> vt;
            ll nw=lca(pos,pos1);
            nw=find_par(nw);

            while (dep[nw]<dep[find_par(pos)])
            {
                pos=find_par(pos);
                ll h=par1[pos];
                dsu(pos,h);

                for (auto to:gr[h])
                {
                    vt.pb(to);
                }
                gr[a[h]].clear();
            }
            swap(pos,pos1);
          //  cout <<pos<<endl;
             while (dep[nw]<dep[find_par(pos)])
            {
                pos=find_par(pos);
                ll h=par1[pos];
                dsu(pos,h);
               // cout <<pos<<" "<<h<<endl;
                for (auto to:gr[a[h]])
                {
                    vt.pb(to);
                }
                gr[a[h]].clear();
            }
            for (auto to:vt)
            {
                ll x=find_par(to);
                st.insert(make_pair(f[x],x));
            }
            ll h=find_par(pos);
            st.insert(make_pair(f[h],h));
        }
    }
    for (int i=1;i<=n;i++) adj[i].clear();
    for (auto to:vt)
    {
        ll x=find_par(to.ff);
        ll y=find_par(to.ss);
        if (x!=y)
        {
           cnt[x]++;
           cnt[y]++;
        }
    }
    ll ans=0;
    ll dem=0;
    for (int i=1;i<=n;i++)
    {
        if (i==find_par(i))
        {
         //  cout <<i<<" "<<cnt[i]<<endl;
            dem++;
            if (cnt[i]==1) ans++;
        }
    }
    if (dem==1) cout <<0<<endl;
    else cout <<(ans+1)/2<<endl;


}

Compilation message

mergers.cpp: In function 'int main()':
mergers.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mergers.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 23756 KB Output is correct
2 Correct 13 ms 23824 KB Output is correct
3 Correct 14 ms 23792 KB Output is correct
4 Correct 14 ms 23812 KB Output is correct
5 Correct 13 ms 23820 KB Output is correct
6 Correct 12 ms 23820 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23828 KB Output is correct
9 Correct 16 ms 23808 KB Output is correct
10 Correct 13 ms 23756 KB Output is correct
11 Correct 14 ms 23784 KB Output is correct
12 Correct 13 ms 23884 KB Output is correct
13 Correct 13 ms 23828 KB Output is correct
14 Correct 12 ms 23840 KB Output is correct
15 Incorrect 12 ms 23884 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 23756 KB Output is correct
2 Correct 13 ms 23824 KB Output is correct
3 Correct 14 ms 23792 KB Output is correct
4 Correct 14 ms 23812 KB Output is correct
5 Correct 13 ms 23820 KB Output is correct
6 Correct 12 ms 23820 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23828 KB Output is correct
9 Correct 16 ms 23808 KB Output is correct
10 Correct 13 ms 23756 KB Output is correct
11 Correct 14 ms 23784 KB Output is correct
12 Correct 13 ms 23884 KB Output is correct
13 Correct 13 ms 23828 KB Output is correct
14 Correct 12 ms 23840 KB Output is correct
15 Incorrect 12 ms 23884 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 23756 KB Output is correct
2 Correct 13 ms 23824 KB Output is correct
3 Correct 14 ms 23792 KB Output is correct
4 Correct 14 ms 23812 KB Output is correct
5 Correct 13 ms 23820 KB Output is correct
6 Correct 12 ms 23820 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23828 KB Output is correct
9 Correct 16 ms 23808 KB Output is correct
10 Correct 13 ms 23756 KB Output is correct
11 Correct 14 ms 23784 KB Output is correct
12 Correct 13 ms 23884 KB Output is correct
13 Correct 13 ms 23828 KB Output is correct
14 Correct 12 ms 23840 KB Output is correct
15 Incorrect 12 ms 23884 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #4
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 124 ms 51336 KB Output is correct
2 Correct 123 ms 54568 KB Output is correct
3 Incorrect 21 ms 24644 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 14 ms 23756 KB Output is correct
2 Correct 13 ms 23824 KB Output is correct
3 Correct 14 ms 23792 KB Output is correct
4 Correct 14 ms 23812 KB Output is correct
5 Correct 13 ms 23820 KB Output is correct
6 Correct 12 ms 23820 KB Output is correct
7 Correct 13 ms 23820 KB Output is correct
8 Correct 13 ms 23828 KB Output is correct
9 Correct 16 ms 23808 KB Output is correct
10 Correct 13 ms 23756 KB Output is correct
11 Correct 14 ms 23784 KB Output is correct
12 Correct 13 ms 23884 KB Output is correct
13 Correct 13 ms 23828 KB Output is correct
14 Correct 12 ms 23840 KB Output is correct
15 Incorrect 12 ms 23884 KB Output isn't correct
16 Halted 0 ms 0 KB -