oj.uz

Submission #676754

# Submission time Handle Problem Language Result Execution time Memory
676754 2023-01-01T03:37:32 Z victor_gao Capital City (JOI20_capital_city) C++17
1 / 100
 2158 ms 387420 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 30
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<=28*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]]--;
        have[i]=0;
    }
}
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)
        all_col[cap[i]]--;
    have[mid]=0;
    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<=28*n;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 63 ms 145960 KB Output is correct
2 Correct 66 ms 145952 KB Output is correct
3 Correct 63 ms 145940 KB Output is correct
4 Correct 66 ms 145968 KB Output is correct
5 Correct 65 ms 145996 KB Output is correct
6 Correct 64 ms 145920 KB Output is correct
7 Correct 65 ms 145980 KB Output is correct
8 Correct 67 ms 146048 KB Output is correct
9 Correct 68 ms 145952 KB Output is correct
10 Correct 64 ms 145920 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 145960 KB Output is correct
2 Correct 66 ms 145952 KB Output is correct
3 Correct 63 ms 145940 KB Output is correct
4 Correct 66 ms 145968 KB Output is correct
5 Correct 65 ms 145996 KB Output is correct
6 Correct 64 ms 145920 KB Output is correct
7 Correct 65 ms 145980 KB Output is correct
8 Correct 67 ms 146048 KB Output is correct
9 Correct 68 ms 145952 KB Output is correct
10 Correct 64 ms 145920 KB Output is correct
11 Correct 77 ms 147484 KB Output is correct
12 Correct 76 ms 147464 KB Output is correct
13 Correct 76 ms 147416 KB Output is correct
14 Correct 69 ms 147516 KB Output is correct
15 Incorrect 71 ms 147652 KB Output isn't correct
16 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 2158 ms 387420 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 59.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 145960 KB Output is correct
2 Correct 66 ms 145952 KB Output is correct
3 Correct 63 ms 145940 KB Output is correct
4 Correct 66 ms 145968 KB Output is correct
5 Correct 65 ms 145996 KB Output is correct
6 Correct 64 ms 145920 KB Output is correct
7 Correct 65 ms 145980 KB Output is correct
8 Correct 67 ms 146048 KB Output is correct
9 Correct 68 ms 145952 KB Output is correct
10 Correct 64 ms 145920 KB Output is correct
11 Correct 77 ms 147484 KB Output is correct
12 Correct 76 ms 147464 KB Output is correct
13 Correct 76 ms 147416 KB Output is correct
14 Correct 69 ms 147516 KB Output is correct
15 Incorrect 71 ms 147652 KB Output isn't correct
16 Halted 0 ms 0 KB -