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Submission #572753

# Submission time Handle Problem Language Result Execution time Memory
572753 2022-06-05T08:39:58 Z MohammadAghil Network (BOI15_net) C++14
100 / 100
 1042 ms 130212 KB 
      #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) x.begin(), x.end()
              #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...);}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll mod = 1e9 + 7, maxn = 5e5 + 5, lg = 22, lng = 26, 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;}

int seg[maxn<<2];
int upd(int i, int k, int x = 1, int lx = 0, int rx = maxn){
     if(lx + 1 == rx) return seg[x] = k, 0;
     int mid = (lx + rx)>>1;
     if(i < mid) upd(i, k, x<<1, lx, mid);
     else upd(i, k, x<<1|1, mid, rx);
     return seg[x] = min(seg[x<<1], seg[x<<1|1]), 0; 
}
int get(int l, int r, int x = 1, int lx = 0, int rx = maxn){
     if(l <= lx && r >= rx) return seg[x];
     if(l >= rx || r <= lx) return inf;
     int mid = (lx + rx)>>1;
     return min(get(l, r, x<<1, lx, mid), get(l, r, x<<1|1, mid, rx));
}

int st[maxn], en[maxn], eu[maxn], t, par[maxn][lg], h[maxn], a[maxn], b[maxn], mtch[maxn];
vector<int> adj[maxn], leaf;

void dfs(int r, int p){
     if(sz(adj[r]) == 1) leaf.pb(t);
     eu[t] = r, st[r] = t++, par[r][0] = p;
     rep(i,1,lg) par[r][i] = par[par[r][i-1]][i-1];
     for(int c: adj[r]) if(c - p) h[c] = h[r] + 1, dfs(c, r);
     en[r] = t;
}

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[u][i] - par[v][i]) u = par[u][i], v = par[v][i];
     return par[u][0];
}

void add(int u, int v){
     mtch[u] = v, mtch[v] = u;
     int l = lca(u, v);
     upd(st[u], h[l]), upd(st[v], h[l]);
}

int main(){
     cin.tie(0) -> sync_with_stdio(0);
     fill(seg, seg+(maxn<<2), inf);
     fill(mtch, mtch + maxn, -1);

     int n; cin >> n;
     rep(i,1,n){
          int u, v; cin >> u >> v; u--, v--;
          adj[u].pb(v);
          adj[v].pb(u);
     }

     int root;
     rep(i,0,n) if(sz(adj[i]) > 1) root = i;
     dfs(root, root);
     // er(root+1);
     // for(int c: leaf) er(eu[c]+1);

     rep(i,0,n) if(i - root){
          a[i] = leaf.back();
          // er(a[i], st[i], en[i]);
          if(st[i] < a[i] && en[i] > a[i]) a[i] = leaf[0];
          b[i] = *lower_bound(all(leaf), st[i]), a[i] = eu[a[i]], b[i] = eu[b[i]];
          // er(i+1, a[i]+1, b[i]+1);
     }

     rep(i,0,sz(leaf)>>1) add(eu[leaf[i<<1]], eu[leaf[i<<1|1]]);
     if(sz(leaf)&1) add(eu[leaf.back()], root);

     rep(i,0,n) if(i - root){
          if(get(st[i], en[i]) < h[i]) continue;
          int x = mtch[a[i]], y = mtch[b[i]];
          add(a[i], b[i]), add(x, y);
     }

     cout << ((sz(leaf)+1)>>1) << '\n';
     vector<bool> is(n);
     rep(i,0,n){
          if(mtch[i]+1 && !is[i]){
               cout << i + 1 << ' ' << mtch[i] + 1 << '\n';
               is[mtch[i]] = true;
          }
     }
     return 0; 
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:89:17: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
   89 |      rep(i,0,n) if(i - root){
      |                 ^~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 21844 KB Output is correct
2 Correct 11 ms 21816 KB Output is correct
3 Correct 11 ms 21872 KB Output is correct
4 Correct 12 ms 21844 KB Output is correct
5 Correct 11 ms 21844 KB Output is correct
6 Correct 11 ms 21844 KB Output is correct
7 Correct 11 ms 21820 KB Output is correct
8 Correct 11 ms 21828 KB Output is correct
9 Correct 11 ms 21896 KB Output is correct
10 Correct 11 ms 21812 KB Output is correct
11 Correct 11 ms 21844 KB Output is correct
12 Correct 11 ms 21844 KB Output is correct
13 Correct 23 ms 21844 KB Output is correct
14 Correct 14 ms 21844 KB Output is correct
15 Correct 13 ms 21864 KB Output is correct
16 Correct 13 ms 21868 KB Output is correct
17 Correct 10 ms 21844 KB Output is correct
18 Correct 10 ms 21844 KB Output is correct
19 Correct 11 ms 21844 KB Output is correct
20 Correct 13 ms 21864 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 21844 KB Output is correct
2 Correct 11 ms 21816 KB Output is correct
3 Correct 11 ms 21872 KB Output is correct
4 Correct 12 ms 21844 KB Output is correct
5 Correct 11 ms 21844 KB Output is correct
6 Correct 11 ms 21844 KB Output is correct
7 Correct 11 ms 21820 KB Output is correct
8 Correct 11 ms 21828 KB Output is correct
9 Correct 11 ms 21896 KB Output is correct
10 Correct 11 ms 21812 KB Output is correct
11 Correct 11 ms 21844 KB Output is correct
12 Correct 11 ms 21844 KB Output is correct
13 Correct 23 ms 21844 KB Output is correct
14 Correct 14 ms 21844 KB Output is correct
15 Correct 13 ms 21864 KB Output is correct
16 Correct 13 ms 21868 KB Output is correct
17 Correct 10 ms 21844 KB Output is correct
18 Correct 10 ms 21844 KB Output is correct
19 Correct 11 ms 21844 KB Output is correct
20 Correct 13 ms 21864 KB Output is correct
21 Correct 11 ms 21844 KB Output is correct
22 Correct 13 ms 22228 KB Output is correct
23 Correct 15 ms 22132 KB Output is correct
24 Correct 13 ms 22136 KB Output is correct
25 Correct 13 ms 22200 KB Output is correct
26 Correct 13 ms 22060 KB Output is correct
27 Correct 14 ms 22132 KB Output is correct
28 Correct 15 ms 22144 KB Output is correct
29 Correct 13 ms 22100 KB Output is correct
30 Correct 11 ms 21844 KB Output is correct
31 Correct 13 ms 22228 KB Output is correct
32 Correct 11 ms 21868 KB Output is correct
33 Correct 11 ms 21904 KB Output is correct
34 Correct 10 ms 21844 KB Output is correct
35 Correct 11 ms 21844 KB Output is correct
36 Correct 11 ms 21844 KB Output is correct
37 Correct 12 ms 21972 KB Output is correct
38 Correct 12 ms 22060 KB Output is correct
39 Correct 16 ms 21912 KB Output is correct
40 Correct 15 ms 21884 KB Output is correct
41 Correct 12 ms 21892 KB Output is correct
42 Correct 11 ms 21972 KB Output is correct
43 Correct 12 ms 21972 KB Output is correct
44 Correct 11 ms 21844 KB Output is correct
45 Correct 11 ms 21872 KB Output is correct
46 Correct 12 ms 21972 KB Output is correct
47 Correct 11 ms 21844 KB Output is correct
48 Correct 11 ms 21844 KB Output is correct
49 Correct 11 ms 21972 KB Output is correct
50 Correct 14 ms 21892 KB Output is correct
51 Correct 11 ms 21916 KB Output is correct
52 Correct 12 ms 21920 KB Output is correct
53 Correct 13 ms 21972 KB Output is correct
54 Correct 12 ms 21844 KB Output is correct
55 Correct 14 ms 21920 KB Output is correct
56 Correct 11 ms 21852 KB Output is correct
57 Correct 11 ms 22000 KB Output is correct
58 Correct 13 ms 22140 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 21844 KB Output is correct
2 Correct 11 ms 21816 KB Output is correct
3 Correct 11 ms 21872 KB Output is correct
4 Correct 12 ms 21844 KB Output is correct
5 Correct 11 ms 21844 KB Output is correct
6 Correct 11 ms 21844 KB Output is correct
7 Correct 11 ms 21820 KB Output is correct
8 Correct 11 ms 21828 KB Output is correct
9 Correct 11 ms 21896 KB Output is correct
10 Correct 11 ms 21812 KB Output is correct
11 Correct 11 ms 21844 KB Output is correct
12 Correct 11 ms 21844 KB Output is correct
13 Correct 23 ms 21844 KB Output is correct
14 Correct 14 ms 21844 KB Output is correct
15 Correct 13 ms 21864 KB Output is correct
16 Correct 13 ms 21868 KB Output is correct
17 Correct 10 ms 21844 KB Output is correct
18 Correct 10 ms 21844 KB Output is correct
19 Correct 11 ms 21844 KB Output is correct
20 Correct 13 ms 21864 KB Output is correct
21 Correct 11 ms 21844 KB Output is correct
22 Correct 13 ms 22228 KB Output is correct
23 Correct 15 ms 22132 KB Output is correct
24 Correct 13 ms 22136 KB Output is correct
25 Correct 13 ms 22200 KB Output is correct
26 Correct 13 ms 22060 KB Output is correct
27 Correct 14 ms 22132 KB Output is correct
28 Correct 15 ms 22144 KB Output is correct
29 Correct 13 ms 22100 KB Output is correct
30 Correct 11 ms 21844 KB Output is correct
31 Correct 13 ms 22228 KB Output is correct
32 Correct 11 ms 21868 KB Output is correct
33 Correct 11 ms 21904 KB Output is correct
34 Correct 10 ms 21844 KB Output is correct
35 Correct 11 ms 21844 KB Output is correct
36 Correct 11 ms 21844 KB Output is correct
37 Correct 12 ms 21972 KB Output is correct
38 Correct 12 ms 22060 KB Output is correct
39 Correct 16 ms 21912 KB Output is correct
40 Correct 15 ms 21884 KB Output is correct
41 Correct 12 ms 21892 KB Output is correct
42 Correct 11 ms 21972 KB Output is correct
43 Correct 12 ms 21972 KB Output is correct
44 Correct 11 ms 21844 KB Output is correct
45 Correct 11 ms 21872 KB Output is correct
46 Correct 12 ms 21972 KB Output is correct
47 Correct 11 ms 21844 KB Output is correct
48 Correct 11 ms 21844 KB Output is correct
49 Correct 11 ms 21972 KB Output is correct
50 Correct 14 ms 21892 KB Output is correct
51 Correct 11 ms 21916 KB Output is correct
52 Correct 12 ms 21920 KB Output is correct
53 Correct 13 ms 21972 KB Output is correct
54 Correct 12 ms 21844 KB Output is correct
55 Correct 14 ms 21920 KB Output is correct
56 Correct 11 ms 21852 KB Output is correct
57 Correct 11 ms 22000 KB Output is correct
58 Correct 13 ms 22140 KB Output is correct
59 Correct 1008 ms 95132 KB Output is correct
60 Correct 962 ms 103340 KB Output is correct
61 Correct 11 ms 21844 KB Output is correct
62 Correct 12 ms 21844 KB Output is correct
63 Correct 743 ms 87252 KB Output is correct
64 Correct 18 ms 22780 KB Output is correct
65 Correct 40 ms 26612 KB Output is correct
66 Correct 262 ms 56540 KB Output is correct
67 Correct 924 ms 130212 KB Output is correct
68 Correct 997 ms 120472 KB Output is correct
69 Correct 26 ms 24524 KB Output is correct
70 Correct 273 ms 48640 KB Output is correct
71 Correct 793 ms 106552 KB Output is correct
72 Correct 801 ms 105340 KB Output is correct
73 Correct 200 ms 44108 KB Output is correct
74 Correct 880 ms 102260 KB Output is correct
75 Correct 79 ms 31192 KB Output is correct
76 Correct 800 ms 106124 KB Output is correct
77 Correct 827 ms 106200 KB Output is correct
78 Correct 108 ms 31540 KB Output is correct
79 Correct 901 ms 113348 KB Output is correct
80 Correct 17 ms 22520 KB Output is correct
81 Correct 296 ms 49760 KB Output is correct
82 Correct 897 ms 104036 KB Output is correct
83 Correct 877 ms 102300 KB Output is correct
84 Correct 911 ms 102264 KB Output is correct
85 Correct 910 ms 102268 KB Output is correct
86 Correct 1042 ms 103288 KB Output is correct
87 Correct 1010 ms 103464 KB Output is correct