oj.uz

Submission #536437

# Submission time Handle Problem Language Result Execution time Memory
536437 2022-03-13T10:13:10 Z cig32 Valley (BOI19_valley) C++17
100 / 100
 155 ms 40436 KB 
#include "bits/stdc++.h"
using namespace std;
const int MAXN = 2e5 + 10;
const int MOD = 120717661;
#define int long long
#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() { // read int128
  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;
}
void precomp() { 
  for(int i=0; i<MAXN; i++) f[i] = (i == 0 ? 1 % MOD : (f[i-1] * i) % MOD);
}

vector<pair<int, int> > adj[MAXN];

int oh[MAXN];
int shop[MAXN];
int x, y; // edge removed
vector<pair<int, int> > edges;
int dep[MAXN];
int tin[MAXN], tout[MAXN];
int par[MAXN];
int wow = 0;
int sz[MAXN];
void dfs(int node, int prv, int cur) {
  oh[node] = 1e18;
  dep[node] = cur;
  tin[node] = ++wow;
  par[node] = prv;
  sz[node] = 1;
  for(auto x: adj[node]) {
    if(x.first != prv) {
      dfs(x.first, node, cur + x.second);
      oh[node] = min(oh[node], oh[x.first]);
      sz[node] += sz[x.first];
    }
  }
  tout[node] = ++wow;
  if(shop[node]) oh[node] = cur;
}

bool cmp(pair<int, int> a, pair<int, int> b) {
  return sz[a.first] > sz[b.first];
}
vector<int> euler2;
void dfs2(int node, int prv) {
  euler2.push_back(node);
  for(auto x: adj[node]) {
    if(x.first != prv) {
      dfs2(x.first, node);
    }
  }
}

int st[19][MAXN];

int query_min(int l, int r ) {
  int k = 32 - __builtin_clz(r-l+1) - 1;
  return min(st[k][l], st[k][r - (1<<k) + 1]);
}

void solve(int tc) {
  int n, s, q, e;
  cin >> n >> s >> q >> e;
  for(int i=1; i<n; i++) {
    int a, b, w;
    cin >> a >> b >> w;
    edges.push_back({a, b});
    adj[a].push_back({b, w});
    adj[b].push_back({a, w});
  }
  for(int i=0; i<s; i++) {
    int c; cin >> c;
    shop[c] = 1;
  }
  dfs(e, -1, 0);
  for(int i=1; i<=n; i++) sort(adj[i].begin(), adj[i].end(), cmp);
  dfs2(e, -1);
  for(int i=0; i<euler2.size(); i++) st[0][i] = oh[euler2[i]] - 2 * dep[euler2[i]];
  for(int i=1; i<19; i++) {
    for(int j=0; j<euler2.size(); j++) {
      if(j + (1<<i) - 1 < euler2.size()) {
        st[i][j] = min(st[i-1][j], st[i-1][j + (1<<(i-1))]);
      }
    }
  }
  int pos[n + 1], dage[n + 1]; // position in euler2 -> position of dage
  for(int i=0; i<n; i++) {
    pos[euler2[i]] = i;
  }
  for(int i=0; i<n; i++) {
    if(i == 0 || !(tin[euler2[i-1]] < tin[euler2[i]] && tout[euler2[i]] < tout[euler2[i-1]])) {
      dage[i] = i;
    }
    else {
      dage[i] = dage[i - 1];
    }
  }
  while(q--) {
    int i, r;
    cin >> i >> r;
    if(n == 1) {
      cout << "escaped\n";
      continue;
    }
    i--;
    x = edges[i].first, y = edges[i].second;
    if(tin[x] > tin[y]) swap(x, y);
    if(!(tin[y] <= tin[r] && tout[r] <= tout[y])) {
      cout << "escaped\n";
    }
    else {
      int og = r;
      int ans = 1e18;

      while(1) {
        int p = pos[r], en = dage[pos[r]];
        if(tin[euler2[en]] < tin[y]) en = pos[y];
        ans = min(ans, dep[og] + query_min(en, p));
        if(euler2[en] != y) r = par[euler2[en]];
        else break;
      }
      cout << (ans >= 1e14 ? "oo" : to_string(ans)) << "\n";
    }
  }
}
int32_t main(){
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
}

Compilation message

valley.cpp: In function 'void solve(long long int)':
valley.cpp:97:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |   for(int i=0; i<euler2.size(); i++) st[0][i] = oh[euler2[i]] - 2 * dep[euler2[i]];
      |                ~^~~~~~~~~~~~~~
valley.cpp:99:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |     for(int j=0; j<euler2.size(); j++) {
      |                  ~^~~~~~~~~~~~~~
valley.cpp:100:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |       if(j + (1<<i) - 1 < euler2.size()) {
      |          ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5208 KB Output is correct
2 Correct 4 ms 5204 KB Output is correct
3 Correct 4 ms 5204 KB Output is correct
4 Correct 5 ms 5204 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5208 KB Output is correct
2 Correct 4 ms 5204 KB Output is correct
3 Correct 4 ms 5204 KB Output is correct
4 Correct 5 ms 5204 KB Output is correct
5 Correct 3 ms 5332 KB Output is correct
6 Correct 4 ms 5332 KB Output is correct
7 Correct 4 ms 5332 KB Output is correct
8 Correct 4 ms 5332 KB Output is correct
9 Correct 3 ms 5332 KB Output is correct
10 Correct 3 ms 5332 KB Output is correct
11 Correct 4 ms 5332 KB Output is correct
12 Correct 3 ms 5332 KB Output is correct
13 Correct 3 ms 5384 KB Output is correct
14 Correct 3 ms 5332 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 140 ms 33604 KB Output is correct
2 Correct 136 ms 33404 KB Output is correct
3 Correct 137 ms 33648 KB Output is correct
4 Correct 140 ms 33984 KB Output is correct
5 Correct 128 ms 34132 KB Output is correct
6 Correct 135 ms 36340 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 5208 KB Output is correct
2 Correct 4 ms 5204 KB Output is correct
3 Correct 4 ms 5204 KB Output is correct
4 Correct 5 ms 5204 KB Output is correct
5 Correct 3 ms 5332 KB Output is correct
6 Correct 4 ms 5332 KB Output is correct
7 Correct 4 ms 5332 KB Output is correct
8 Correct 4 ms 5332 KB Output is correct
9 Correct 3 ms 5332 KB Output is correct
10 Correct 3 ms 5332 KB Output is correct
11 Correct 4 ms 5332 KB Output is correct
12 Correct 3 ms 5332 KB Output is correct
13 Correct 3 ms 5384 KB Output is correct
14 Correct 3 ms 5332 KB Output is correct
15 Correct 140 ms 33604 KB Output is correct
16 Correct 136 ms 33404 KB Output is correct
17 Correct 137 ms 33648 KB Output is correct
18 Correct 140 ms 33984 KB Output is correct
19 Correct 128 ms 34132 KB Output is correct
20 Correct 135 ms 36340 KB Output is correct
21 Correct 125 ms 36216 KB Output is correct
22 Correct 135 ms 36040 KB Output is correct
23 Correct 149 ms 36176 KB Output is correct
24 Correct 146 ms 36736 KB Output is correct
25 Correct 128 ms 39696 KB Output is correct
26 Correct 121 ms 36484 KB Output is correct
27 Correct 131 ms 36272 KB Output is correct
28 Correct 136 ms 36512 KB Output is correct
29 Correct 151 ms 36640 KB Output is correct
30 Correct 155 ms 38092 KB Output is correct
31 Correct 119 ms 36980 KB Output is correct
32 Correct 125 ms 36912 KB Output is correct
33 Correct 146 ms 37164 KB Output is correct
34 Correct 144 ms 37464 KB Output is correct
35 Correct 135 ms 40436 KB Output is correct
36 Correct 128 ms 37432 KB Output is correct