Submission #554349

# Submission time Handle Problem Language Result Execution time Memory
554349 2022-04-28T07:52:56 Z leaked Pastiri (COI20_pastiri) C++17
0 / 100
683 ms 339624 KB
#include <bits/stdc++.h>

#define f first
#define s second
#define m_p make_pair
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define pw(x) (1LL<<(x))
#define sz(x) (int)(x).size()
#define vec vector

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
template<class T> bool umin(T &a,const T &b){return (a>b?a=b,1:0);}
template<class T> bool umax(T &a,const T &b){return (a<b?a=b,1:0);}
const int N=5e5+1;

vec<int> who[N],g[N],gr[2*N];
int used[2*N],n,k,dst[N],cnt[N];
int m;
vec<int> dp[2*N];

vec<vec<int>> pref[2*N],suf[2*N];
struct dsu{
    int p[2*N];
    int cnt[2*N];
    dsu(){
        iota(p,p+2*N,0);
        fill(cnt,cnt+2*N,1);
    }
    int get(int v){
        return p[v]=(p[v]==v?v:get(p[v]));
    }
    bool mg(int a,int b){
        a=get(a),b=get(b);
        if(a==b) return 0;
        p[a]=b;cnt[b]+=cnt[a];
        return 1;
    }
}ds;

void dfs1(int v,int p){
    used[v]=1;
    ///DP
    for(auto &z : gr[v]){
        if(z==p) continue;
        if(used[z]){
            assert(false);
        }
        dfs1(z,v);
    }
    dp[v].resize(2);
    if(v>=n){
        dp[v][0]=0;
        dp[v][1]=1e9;
        for(auto &z : gr[v]){
            if(z==p) continue;
            pref[v].pb(dp[v]);
            vec<int>ndp(2,1e9);
            for(int t=0;t<2;t++){
                for(int j=0;j<2;j++){
                    umin(ndp[t|j],dp[z][t]+dp[v][j]);
                }
            }
            for(int t=0;t<2;t++) dp[v][t]=ndp[t];
        }

        dp[v][0]=0;dp[v][1]=1e9;
        reverse(all(gr[v]));
        for(auto &z : gr[v]){
            if(z==p) continue;
            suf[v].pb(dp[v]);
            vec<int>ndp(2,1e9);
            for(int t=0;t<2;t++){
                for(int j=0;j<2;j++){
                    umin(ndp[t|j],dp[z][t]+dp[v][j]);
                }
            }
            for(int t=0;t<2;t++) dp[v][t]=ndp[t];
        }
    }
    else{
        dp[v][0]=0;
        dp[v][1]=1;
        for(auto &z : gr[v]){
            if(z==p) continue;
            pref[v].pb(dp[v]);
            vec<int>ndp(2,1e9);
//            umin(ndp[1],dp[v][0]+1+dp[z][0]);
            ///dont need it
            umin(ndp[1],dp[v][1]+dp[z][0]);
            umin(ndp[0],dp[v][0]+dp[z][1]);
            umin(ndp[1],dp[v][1]+dp[z][1]);

            for(int t=0;t<2;t++) dp[v][t]=ndp[t];
        }

        dp[v][0]=0;dp[v][1]=1;
        reverse(all(gr[v]));
        for(auto &z : gr[v]){
            if(z==p) continue;
            suf[v].pb(dp[v]);
            vec<int>ndp(2,1e9);
//            umin(ndp[1],dp[v][0]+1+dp[z][0]);
            ///dont need it
            umin(ndp[1],dp[v][1]+dp[z][0]);
            umin(ndp[0],dp[v][0]+dp[z][1]);
            umin(ndp[1],dp[v][1]+dp[z][1]);

            for(int t=0;t<2;t++) dp[v][t]=ndp[t];
        }
    }
    reverse(all(suf[v]));
    used[v]=2;
}

vec<int> ans;
void dfs2(int v,int p,int j,int need){
    int wi=0;
    int cur=0;
    if(v<n && j){
        ans.pb(v);
        wi=1;
    }
    if(v<n){
        int id=0;
        for(auto &z : gr[v]){
            if(z==p) continue;
            for(int t=0;t<2;t++){
                int ok=0;
                for(int k=0;k<2;k++){
                    if(((wi|t)|k)==j && (cur+suf[v][id][k]+dp[z][t])){
                        ok=1;
                    }
                }
                if(ok){
                    cur+=dp[z][t];
                    dfs2(z,v,t,dp[z][t]);
                    break;
                }
            }
            id++;
        }
    }
    else{
        int id=0;
        for(auto &z : gr[v]){
            if(z==p) continue;
            if(j && (cur+suf[v][id][1]+dp[z][0])==need)
                dfs2(z,v,0,dp[z][0]),cur+=dp[z][0];
            else
                dfs2(z,v,1,dp[z][1]),cur+=dp[z][1];
            id++;
        }
    }
}
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    cin>>n>>k;
    fill(dst,dst+n,1e9);

    for(int i=1;i<n;i++){
        int v,u;
        cin>>v>>u;--v;--u;
        g[v].pb(u);g[u].pb(v);
    }

    queue<int>q;
    int m=k;
    fill(cnt,cnt+n,2);
    for(int i=0;i<k;i++){
        int v;
        cin>>v;--v;
        dst[v]=0;
        who[v].pb(i);
        q.push(v);
    }
    vec<int> vc;
    while(!q.empty()){
        int v=q.front();q.pop();
        vc.pb(v);
        for(auto &z : g[v]){
            if(dst[z]==1e9){
                dst[z]=dst[v]+1;
                q.push(z);
                who[z]=who[v];
                ++cnt[z];
            }
            else if(dst[z]==dst[v]+1){
                ++cnt[z];
                for(auto &u : who[v])
                    who[z].pb(u);
            }
        }
    }
    reverse(all(vc));
    vec<int> ust(2*n,-1);
    int tt=0;

    int s=0;
    ///DEBUG
    for(auto &i : vc){
        if(cnt[i]==1) continue;
        ++tt;
        int ok=0;
        s+=sz(who[i]);
//        cout<<"I "<<i<<' '<<ok<endl;
        for(auto &z : who[i]){
            if(ust[ds.get(z+n)]!=tt) ok++;
            if(ds.cnt[ds.get(z+n)]==1) ++ok;
            ust[ds.get(z+n)]=tt;
        }
//        cout<<ok<<endl;
        if(ok==1) continue;
        for(auto &z : who[i]){
            gr[i].pb(z+n),gr[z+n].pb(i);
            ds.mg(i,z+n);
//            cout<<i<<' '<<z+n<<endl;
        }
        for(auto &z : g[i]){
            if(dst[z]==(dst[i]-1))
                cnt[z]=1;
        }
//        for(auto &v : who[i])
//            cout<<v<<' ';
//        cout<<endl;
    }
//    dfs1(n,-1);
    for(int i=0;i<k;i++){
        if(!used[i+n]){
            dfs1(i+n,-1);
//            ans+=dp[i+n][1];
            dfs2(i+n,-1,1,dp[i+n][1]);
        }
    }
    cout<<sz(ans)<<endl;
    for(auto &z : ans)
        cout<<z+1<<' ';
//    cout<<ans<<endl;
//    cout<<dp[n][1]<<endl;
//    cout<<s<<endl;
    return 0;
}

Compilation message

pastiri.cpp: In function 'int main()':
pastiri.cpp:171:9: warning: unused variable 'm' [-Wunused-variable]
  171 |     int m=k;
      |         ^
# Verdict Execution time Memory Grader output
1 Correct 207 ms 166604 KB Output is correct
2 Incorrect 360 ms 168708 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 156 ms 255288 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 165 ms 254780 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 683 ms 339624 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -