oj.uz

Submission #676755

# Submission time Handle Problem Language Result Execution time Memory
676755 2023-01-01T03:44:32 Z victor_gao Capital City (JOI20_capital_city) C++17
1 / 100
 1625 ms 320492 KB 
//#pragma GCC optimize("Ofast,unroll-loops,O3")
//#pragma GCC optimize("avx,avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,fma,tune=native")
#include<bits/stdc++.h>
//#include<bits/extc++.h>
//#pragma pack(1)
#define fast ios::sync_with_stdio(0); cin.tie(0);
#define pii pair<int,int>
#define x first
#define y second
#define N 200015
#define C 25
using namespace std;
//using namespace __gnu_pbds;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//typedef tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update> order_multiset;
//typedef tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> order_set;
int n,k;
struct SCC{
    vector<int>g[C*N];
    vector<pii>edge;
    int dfn[C*N],low[C*N],dft=0,boss[C*N],val[C*N],dp[C*N],nscc=0;
    bool ins[C*N],vis[C*N];
    stack<int>st;
    void add_edge(int i,int j){
        // i -> j
        g[i].push_back(j);
        edge.push_back({i,j});
    }
    void tarjan(int p){
        dfn[p]=low[p]=++dft;
        st.push(p); ins[p]=1;
        for (auto i:g[p]){
            if (!dfn[i]){
                tarjan(i);
                low[p]=min(low[p],low[i]);
            }
            else if (ins[i]&&dfn[i]<dfn[p])
                low[p]=min(low[p],dfn[i]);
        }
        if (low[p]==dfn[p]){
            nscc++;
        //    cout<<"find cycle "<<nscc<<" : ";
            for (int x=0;x!=p;st.pop()){
                x=st.top(); ins[x]=0;
                boss[x]=nscc;
                if (x<=k) val[nscc]++;
    //            cout<<x<<" ";
            }
     //       cout<<"val "<<val[nscc]<<'\n';
        }
    }
    void build(){
        for (int i=0;i<C*n;i++)
            g[i].clear();
        for (auto i:edge){
            if (boss[i.x]!=boss[i.y]){
    //            cout<<"edge "<<boss[i.x]<<' '<<boss[i.y]<<'\n';
                g[boss[i.x]].push_back(boss[i.y]);
            }
        }
    }
    int dfs(int p){
        if (vis[p]) return dp[p];
        vis[p]=1; dp[p]=val[p];
        for (auto i:g[p])
            dp[p]+=dfs(i);
        return dp[p];
    }
}scc;
int cap[N],vis[N],son[N],all_col[N],sub_col[N],fa[N],have[N];
vector<int>g[N],path,sub_path;
int get_centroid(int p,int lp,int sz){
    for (auto i:g[p]){
        if (!vis[i]&&i!=lp&&son[i]>sz/2)
            return get_centroid(i,p,sz);
    }
    return p;
}
int dfs1(int p,int lp){
    son[p]=1;
    path.push_back(p);
    for (auto i:g[p]){
        if (!vis[i]&&i!=lp)
            son[p]+=dfs1(i,p);
    }
    return son[p];
}
void dfs2(int p,int lp){
    fa[p]=lp;
    sub_path.push_back(p);
    for (auto i:g[p]){
        if (!vis[i]&&i!=lp)
            dfs2(i,p);
    }
}
void build(int root,int dep){
    for (auto i:sub_path){
        sub_col[cap[i]]++;
        scc.add_edge(dep*n+i,cap[i]);
  //      cout<<"add_1 "<<dep*n+i<<' '<<cap[i]<<'\n';
    }
    /*
    cout<<"sub_col ";
    for (int i=1;i<=k;i++)
        cout<<sub_col[i]<<' ';
    cout<<'\n';
    */
    for (auto i:sub_path){
        if (all_col[cap[i]]==sub_col[cap[i]])
            continue;
        int p=i;
      //  cout<<"try "<<i<<" "<<cap[i]<<'\n';
        while (!have[p]){
            scc.add_edge(cap[i],dep*n+fa[p]);
          //  cout<<"add_2 "<<cap[i]<<" "<<dep*n+fa[p]<<'\n';
            have[p]=1; p=fa[p];
        }
    }
    for (auto i:sub_path)
        sub_col[cap[i]]--;
}
void Cut(int p,int lp,int dep){
    path.clear();
  //  cout<<p<<" "<<lp<<" "<<dep<<'\n';
    int sz=dfs1(p,lp);
    int mid=get_centroid(p,lp,sz);
  //  cout<<mid<<" : \n";
    vis[mid]=1; have[mid]=1;
    scc.add_edge(dep*n+mid,cap[mid]);
 //   cout<<"add1 "<<dep*n+mid<<" "<<cap[mid]<<'\n';
    for (auto i:path)
        all_col[cap[i]]++;
 //   cout<<"all_col ";
  //  for (int i=1;i<=k;i++)
  //      cout<<all_col[i]<<" ";
  //  cout<<'\n';
    for (auto i:g[mid]){
        if (vis[i]) continue;
        dfs2(i,mid);
        build(i,dep);
        sub_path.clear();
    }
    for (auto i:path){
        have[i]=0;
        all_col[cap[i]]--;
    }
    for (auto i:g[mid]){
        if (!vis[i])
            Cut(i,mid,dep+1);
    }
}
signed main(){
    fast
    cin>>n>>k;
    for (int i=1;i<n;i++){
        int a,b; cin>>a>>b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for (int i=1;i<=n;i++)
        cin>>cap[i];
    Cut(1,0,1);
    for (int i=1;i<=k;i++){
        if (!scc.dfn[i])
            scc.tarjan(i);
    }
    scc.build();
    int ans=k;
    for (int i=1;i<=k;i++){
  //      cout<<scc.boss[i]<<" "<<scc.dfs(scc.boss[i])<<'\n';
        ans=min(scc.dfs(scc.boss[i]),ans);
    }
    cout<<ans-1<<'\n';
}

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 54 ms 122444 KB Output is correct
2 Correct 55 ms 122508 KB Output is correct
3 Correct 66 ms 122472 KB Output is correct
4 Correct 55 ms 122512 KB Output is correct
5 Correct 53 ms 122532 KB Output is correct
6 Correct 55 ms 122464 KB Output is correct
7 Correct 55 ms 122440 KB Output is correct
8 Correct 56 ms 122512 KB Output is correct
9 Correct 55 ms 122444 KB Output is correct
10 Correct 55 ms 122444 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 54 ms 122444 KB Output is correct
2 Correct 55 ms 122508 KB Output is correct
3 Correct 66 ms 122472 KB Output is correct
4 Correct 55 ms 122512 KB Output is correct
5 Correct 53 ms 122532 KB Output is correct
6 Correct 55 ms 122464 KB Output is correct
7 Correct 55 ms 122440 KB Output is correct
8 Correct 56 ms 122512 KB Output is correct
9 Correct 55 ms 122444 KB Output is correct
10 Correct 55 ms 122444 KB Output is correct
11 Correct 59 ms 123492 KB Output is correct
12 Correct 64 ms 123464 KB Output is correct
13 Correct 62 ms 123644 KB Output is correct
14 Correct 59 ms 123508 KB Output is correct
15 Incorrect 59 ms 123768 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 1625 ms 320492 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 59.0

# Verdict Execution time Memory Grader output
1 Correct 54 ms 122444 KB Output is correct
2 Correct 55 ms 122508 KB Output is correct
3 Correct 66 ms 122472 KB Output is correct
4 Correct 55 ms 122512 KB Output is correct
5 Correct 53 ms 122532 KB Output is correct
6 Correct 55 ms 122464 KB Output is correct
7 Correct 55 ms 122440 KB Output is correct
8 Correct 56 ms 122512 KB Output is correct
9 Correct 55 ms 122444 KB Output is correct
10 Correct 55 ms 122444 KB Output is correct
11 Correct 59 ms 123492 KB Output is correct
12 Correct 64 ms 123464 KB Output is correct
13 Correct 62 ms 123644 KB Output is correct
14 Correct 59 ms 123508 KB Output is correct
15 Incorrect 59 ms 123768 KB Output isn't correct
16 Halted 0 ms 0 KB -