Submission #601399

#	Time	Username	Problem	Language	Result	Execution time	Memory
601399		MohammadAghil	Pastiri (COI20_pastiri)	C++17	23 / 100	1091 ms	158112 KiB

pastiri

      #include <bits/stdc++.h>
//   #pragma GCC optimize ("Ofast,unroll-loops")
// #pragma GCC target ("avx2")
    using namespace std;
  typedef long long ll;
   typedef pair<int, int> pp;
    #define er(args ...) cerr << __LINE__ << ": ", err(new istringstream(string(#args)), args), cerr << endl
      #define per(i,r,l) for(int i = (r); i >= (l); i--)
        #define rep(i,l,r) for(int i = (l); i < (r); i++)
           #define all(x) begin(x), end(x)
              #define sz(x) (int)(x).size()
                  #define pb push_back
                      #define ss second
                           #define ff first
                                   void err(istringstream *iss){}template<typename T,typename ...Args> void err(istringstream *iss,const T &_val, const Args&...args){string _name;*iss>>_name;if(_name.back()==',')_name.pop_back();cerr<<_name<<" = "<<_val<<", ",err(iss,args...);}
void IOS(){
     cin.tie(0) -> sync_with_stdio(0);
     // #ifndef ONLINE_JUDGE
     //      freopen("in.in", "r", stdin);
     //      freopen("out.out", "w", stdout);
     // #endif
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll mod = 1e9 + 7, maxn = 5e5 + 5, lg = 22, inf = ll(1e9) + 5;
ll pw(ll a,ll b,ll md=mod){if(!b)return 1;ll k=pw(a,b>>1ll);return k*k%md*(b&1ll?a:1)%md;}

vector<int> adj[maxn], nd;
set<int> st[maxn];
int par[maxn][lg], h[maxn], cnt[maxn], nxt[maxn], vl[maxn], mn[maxn];
bool ban[maxn];

void dfs(int r, int p){
     par[r][0] = p;
     // er(r);
     rep(i,1,lg) par[r][i] = par[par[r][i-1]][i-1];
     // er(r);
     for(int c: adj[r]) if(c - p) h[c] = h[r] + 1, dfs(c, r);
}

int lca(int u, int v){
     if(h[u] > h[v]) swap(u, v);
     per(i,lg-1,0) if(h[par[v][i]] >= h[u]) v = par[v][i];
     if(u == v) return u;
     per(i,lg-1,0) if(par[v][i] - par[u][i]) u = par[u][i], v = par[v][i];
     return par[u][0]; 
}

void dfs2(int r, int p){
     cnt[r] = 1;
     for(int c: adj[r]) if(c - p && !ban[c]) dfs2(c, r), cnt[r] += cnt[c];
}

int find_cent(int r, int p, int tot){
     for(int c: adj[r]) if(c - p && !ban[c] && (cnt[c]<<1) > tot) return find_cent(c, r, tot);
     return r;
}

void decom(int r, int tp){
     dfs2(r, -1);
     r = find_cent(r, -1, cnt[r]);
     nxt[r] = tp, ban[r] = true;
     for(int c: adj[r]) if(!ban[c]) decom(c, r);
}

int dist(int u, int v){
     return h[u] + h[v] - (h[lca(u, v)]<<1);
}

void bfs(){
     fill(mn, mn + maxn, inf);
     deque<int> q;
     for(int c: nd) mn[c] = 0, q.pb(c);
     while(sz(q)){
          int r = q.front(); q.pop_front();
          for(int c: adj[r]) if(mn[c] == inf) mn[c] = mn[r] + 1, q.pb(c);
     }
}


int main(){ IOS();
     int n, k; cin >> n >> k;
     rep(i,1,n){
          int u, v; cin >> u >> v; u--, v--;
          adj[u].pb(v), adj[v].pb(u);
     }
     nd.resize(k);
     rep(i,0,k) cin >> nd[i], nd[i]--;

     dfs(0, 0);
     // er(n);
     decom(0, -1), bfs();

     // rep(i,0,n) er(i+1, mn[i]);

     sort(all(nd), [&](int i, int j){ return h[i] > h[j]; });
     vector<int> ans;
     auto add = [&](int u){
          ans.pb(u);
          int cr = u;
          while(cr + 1){
               int d = dist(u, cr);
               // er(cr);
               if(mn[u] >= d) st[cr].insert(mn[u] - d);
               cr = nxt[cr];
          }
     };

     auto chk = [&](int u){
          int cr = u;
          while(cr + 1){
               // er(sz(st[cr]));
               if(st[cr].find(dist(cr, u)) != end(st[cr])) return true;
               // er(sz(st[cr]));
               cr = nxt[cr];
          }
          return false;
     };

     auto get = [&](int u){
          int k = u;
          per(i,lg-1,0) if(h[u] - h[par[k][i]] == mn[par[k][i]]) k = par[k][i];
          return k;
     };

     for(int c: nd){
          if(chk(c)) continue;
          // er(c+1, get(c)+1);
          add(get(c));
     }

     cout << sz(ans) << '\n'; sort(all(ans));
     for(int c: ans) cout << ++c << ' '; cout << '\n';
     return 0; 
}

Compilation message (stderr)

pastiri.cpp: In function 'int main()':
pastiri.cpp:132:6: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  132 |      for(int c: ans) cout << ++c << ' '; cout << '\n';
      |      ^~~
pastiri.cpp:132:42: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  132 |      for(int c: ans) cout << ++c << ' '; cout << '\n';
      |                                          ^~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 18
• Subtask 3: 23 / 23
• Subtask 4: 0 / 51