oj.uz

답안 #678484

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
678484 2023-01-06T04:43:50 Z cig32 The Xana coup (BOI21_xanadu) C++17
100 / 100
 96 ms 40024 KB 
#include "bits/stdc++.h"
using namespace std;
#define int long long
const int MAXN = 3e5 + 10;
const int MOD = 1e9 + 7;
#define ll __int128
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
ll read() { int x; cin >> x; return (ll)x; }
long long bm(long long b, long long p) {
  if(p==0) return 1 % MOD;
  long long r = bm(b, p >> 1);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
long long inv(long long b) { 
  return bm(b, MOD-2);
}
long long f[MAXN];
long long nCr(int n, int r) { 
  long long ans = f[n]; ans *= inv(f[r]); ans %= MOD;
  ans *= inv(f[n-r]); ans %= MOD; return ans;
}
long long fib[MAXN], lucas[MAXN];
void precomp() { 
  for(int i=0; i<MAXN; i++) f[i] = (i == 0 ? 1 % MOD : (f[i-1] * i) % MOD); 
  lucas[0] = 2;
  lucas[1] = 1;
  for(int i=2; i<MAXN; i++) lucas[i] = (lucas[i-2] + lucas[i-1]) % MOD;
  fib[0] = 0;
  fib[1] = 1;
  for(int i=2; i<MAXN; i++) fib[i] = (fib[i-2] + fib[i-1]) % MOD;
}
int fastlog(int x) {
  return (x == 0 ? -1 : 64 - __builtin_clzll(x) - 1);
}
void gay(int i) { cout << "Case #" << i << ": "; }
int csb(int l, int r, int k) { // count number of [l, r] such that i & 2^k > 0
  if(l > r) return 0;
  if(l == 0) {
    int s = r / (1ll << (k+1)); // number of complete cycles
    int t = r % (1ll << (k+1));
    int ans = s * (1ll << k);
    ans += (t >= (1ll << k) ? t - (1ll << k) + 1 : 0);
    return ans;
  }
  else return csb(0, r, k) - csb(0, l - 1, k);
}
int lis(vector<int> a) {
  int n = a.size();
  int bucket[n+1];
  for(int i=1; i<=n; i++) bucket[i] = 1e18;
  int ans = 1;
  for(int x: a) {
    auto it = lower_bound(bucket + 1, bucket +n +1, x);
    int d = distance(bucket, it);
    ans = max(ans, d);
    bucket[d] = min(bucket[d], x);
  }
  return ans;
}
 
int n;
vector<int> adj[MAXN];
int ogname[MAXN];
 
int dp[MAXN][2][2];
void dfs(int node, int prv) {
  vector<int> vt;
  for(int x: adj[node]) {
    if(x != prv) {
      dfs(x, node);
      vt.push_back(x);
    }
  }
  int m = vt.size();
 
  if(m == 0) {
    dp[node][ogname[node]][0] = 0;
    dp[node][(1 ^ ogname[node])][1] = 1;
    return;
  }
 
  int sub0[m][2], sub1[m][2];
  for(int i=0; i<m; i++) for(int j=0; j<2; j++) sub0[i][j] = sub1[i][j] = 1e9;  
  
  sub0[0][0] = dp[vt[0]][0][0];
  sub0[0][1] = dp[vt[0]][0][1];
 
  sub1[0][0] = dp[vt[0]][1][0];
  sub1[0][1] = dp[vt[0]][1][1];
 
  for(int i=1; i<m; i++) {
    sub0[i][0] = min(sub0[i-1][0] + dp[vt[i]][0][0], sub0[i-1][1] + dp[vt[i]][0][1]);
    sub0[i][1] = min(sub0[i-1][0] + dp[vt[i]][0][1], sub0[i-1][1] + dp[vt[i]][0][0]);
 
    sub1[i][0] = min(sub1[i-1][0] + dp[vt[i]][1][0], sub1[i-1][1] + dp[vt[i]][1][1]);
    sub1[i][1] = min(sub1[i-1][0] + dp[vt[i]][1][1], sub1[i-1][1] + dp[vt[i]][1][0]);
  }
  
  // Compute dp[node][0][1]: dp[vt[j]][1][x], sum of x mod 2 = (1 ^ ogname)
 
  dp[node][0][1] = sub1[m-1][(1 ^ ogname[node])] + 1;
  dp[node][1][0] = sub0[m-1][(1 ^ ogname[node])];
 
  dp[node][0][0] = sub0[m-1][ogname[node]];
  dp[node][1][1] = sub1[m-1][ogname[node]] + 1;
  
  /*
  for(int i=0; i<(1<<m); i++) {
    int st = ogname[node];
    for(int j=0; j<m; j++) {
      int bit = (i & (1<<j));
      if(bit > 0) st ^= 1;
    }
    // st = current state
    if(st) { // cur state = 1
      // if final state = 0 (Toggle node)
      int sm = 0;
      for(int j=0; j<m; j++) {
        if(i & (1<<j)) sm += dp[vt[j]][1][1];
        else sm += dp[vt[j]][1][0];
      }
      dp[node][0][1] = min(dp[node][0][1], sm + 1); 
      // if final state = 1 (Don't toggle node)
      sm = 0;
      for(int j=0; j<m; j++) {
        if(i & (1<<j)) sm += dp[vt[j]][0][1];
        else sm += dp[vt[j]][0][0];
      }
      dp[node][1][0] = min(dp[node][1][0], sm); 
 
    }
    else { // cur state = 0
 
      // if final state = 0 (Don't toggle node)
      int sm = 0;
      for(int j=0; j<m; j++) {
        if(i & (1<<j)) sm += dp[vt[j]][0][1];
        else sm += dp[vt[j]][0][0];
      }
      dp[node][0][0] = min(dp[node][0][0], sm); 
      // if final state = 1 (Toggle node)
      sm = 0;
      for(int j=0; j<m; j++) {
        if(i & (1<<j)) sm += dp[vt[j]][1][1];
        else sm += dp[vt[j]][1][0];
      }
      dp[node][1][1] = min(dp[node][1][1], sm + 1); 
      
    }
 
  }
  */
}
void solve(int tc) {
  cin >> n;
  for(int i=2; i<=n; i++) {
    int a, b;
    cin >> a >> b;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }
 
  for(int i=1; i<=n; i++) {
    for(int j=0; j<2; j++) {
      for(int k=0; k<2; k++) {
        dp[i][j][k] = 1e9;
      }
    }
  }
 
  for(int i=1; i<=n; i++) {
    cin >> ogname[i];
  }
 
  dfs(1, -1);
 
  cout << (min(dp[1][0][0], dp[1][0][1]) >= 1e8 ? "impossible" : to_string(min(dp[1][0][0], dp[1][0][1]))) << "\n";
 
  //cout << dp[4]
 
}
int32_t main() {
  precomp();
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 14424 KB Output is correct
2 Correct 13 ms 14412 KB Output is correct
3 Correct 13 ms 14420 KB Output is correct
4 Correct 12 ms 14416 KB Output is correct
5 Correct 12 ms 14420 KB Output is correct

Subtask #2
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 14424 KB Output is correct
2 Correct 13 ms 14412 KB Output is correct
3 Correct 13 ms 14420 KB Output is correct
4 Correct 12 ms 14416 KB Output is correct
5 Correct 12 ms 14420 KB Output is correct
6 Correct 12 ms 14416 KB Output is correct
7 Correct 12 ms 14420 KB Output is correct
8 Correct 11 ms 14420 KB Output is correct
9 Correct 13 ms 14420 KB Output is correct
10 Correct 12 ms 14420 KB Output is correct
11 Correct 12 ms 14396 KB Output is correct
12 Correct 11 ms 14420 KB Output is correct
13 Correct 11 ms 14420 KB Output is correct
14 Correct 13 ms 14308 KB Output is correct
15 Correct 12 ms 14420 KB Output is correct
16 Correct 11 ms 14420 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 76 ms 39780 KB Output is correct
2 Correct 68 ms 39500 KB Output is correct
3 Correct 81 ms 39960 KB Output is correct

Subtask #4
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 75 ms 39876 KB Output is correct
2 Correct 71 ms 39484 KB Output is correct
3 Correct 64 ms 40024 KB Output is correct
4 Correct 78 ms 22632 KB Output is correct
5 Correct 91 ms 23388 KB Output is correct
6 Correct 96 ms 23632 KB Output is correct
7 Correct 15 ms 14404 KB Output is correct
8 Correct 30 ms 17424 KB Output is correct
9 Correct 65 ms 23296 KB Output is correct
10 Correct 77 ms 23432 KB Output is correct
11 Correct 71 ms 24376 KB Output is correct
12 Correct 76 ms 24912 KB Output is correct
13 Correct 76 ms 23396 KB Output is correct
14 Correct 68 ms 23980 KB Output is correct

Subtask #5
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 14424 KB Output is correct
2 Correct 13 ms 14412 KB Output is correct
3 Correct 13 ms 14420 KB Output is correct
4 Correct 12 ms 14416 KB Output is correct
5 Correct 12 ms 14420 KB Output is correct
6 Correct 12 ms 14416 KB Output is correct
7 Correct 12 ms 14420 KB Output is correct
8 Correct 11 ms 14420 KB Output is correct
9 Correct 13 ms 14420 KB Output is correct
10 Correct 12 ms 14420 KB Output is correct
11 Correct 12 ms 14396 KB Output is correct
12 Correct 11 ms 14420 KB Output is correct
13 Correct 11 ms 14420 KB Output is correct
14 Correct 13 ms 14308 KB Output is correct
15 Correct 12 ms 14420 KB Output is correct
16 Correct 11 ms 14420 KB Output is correct
17 Correct 76 ms 39780 KB Output is correct
18 Correct 68 ms 39500 KB Output is correct
19 Correct 81 ms 39960 KB Output is correct
20 Correct 75 ms 39876 KB Output is correct
21 Correct 71 ms 39484 KB Output is correct
22 Correct 64 ms 40024 KB Output is correct
23 Correct 78 ms 22632 KB Output is correct
24 Correct 91 ms 23388 KB Output is correct
25 Correct 96 ms 23632 KB Output is correct
26 Correct 15 ms 14404 KB Output is correct
27 Correct 30 ms 17424 KB Output is correct
28 Correct 65 ms 23296 KB Output is correct
29 Correct 77 ms 23432 KB Output is correct
30 Correct 71 ms 24376 KB Output is correct
31 Correct 76 ms 24912 KB Output is correct
32 Correct 76 ms 23396 KB Output is correct
33 Correct 68 ms 23980 KB Output is correct
34 Correct 14 ms 14396 KB Output is correct
35 Correct 12 ms 14416 KB Output is correct
36 Correct 12 ms 14380 KB Output is correct
37 Correct 11 ms 14420 KB Output is correct
38 Correct 12 ms 14348 KB Output is correct
39 Correct 11 ms 14420 KB Output is correct
40 Correct 11 ms 14404 KB Output is correct
41 Correct 11 ms 14412 KB Output is correct
42 Correct 11 ms 14420 KB Output is correct
43 Correct 13 ms 14420 KB Output is correct
44 Correct 13 ms 14532 KB Output is correct
45 Correct 76 ms 39876 KB Output is correct
46 Correct 63 ms 39492 KB Output is correct
47 Correct 69 ms 40020 KB Output is correct
48 Correct 59 ms 22700 KB Output is correct
49 Correct 77 ms 23400 KB Output is correct
50 Correct 78 ms 23644 KB Output is correct
51 Correct 11 ms 14420 KB Output is correct
52 Correct 27 ms 17492 KB Output is correct
53 Correct 66 ms 23248 KB Output is correct
54 Correct 74 ms 23548 KB Output is correct
55 Correct 85 ms 24492 KB Output is correct
56 Correct 73 ms 24828 KB Output is correct
57 Correct 73 ms 23320 KB Output is correct
58 Correct 67 ms 23908 KB Output is correct
59 Correct 27 ms 17320 KB Output is correct
60 Correct 65 ms 22448 KB Output is correct
61 Correct 69 ms 23176 KB Output is correct
62 Correct 70 ms 23368 KB Output is correct
63 Correct 70 ms 23468 KB Output is correct
64 Correct 69 ms 23380 KB Output is correct
65 Correct 64 ms 23860 KB Output is correct
66 Correct 54 ms 23756 KB Output is correct
67 Correct 49 ms 27596 KB Output is correct
68 Correct 50 ms 27628 KB Output is correct
69 Correct 50 ms 27600 KB Output is correct
70 Correct 50 ms 27532 KB Output is correct