oj.uz

Submission #229687

# Submission time Handle Problem Language Result Execution time Memory
229687 2020-05-05T22:52:00 Z xiaowuc1 None (KOI16_tree) C++14
9 / 100
 497 ms 51448 KB 
#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <complex>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <vector>

using namespace std;

// BEGIN NO SAD
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define derr if(1) cerr
typedef vector<int> vi;
// END NO SAD

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<vector<ll>> matrix;
typedef pair<int, pii> state;

const int KOOSAGA_DEPTH = 18;
const int KOOSAGA_SZ = 1 << KOOSAGA_DEPTH;
bool koosagatree[2 * KOOSAGA_SZ];
void upd(int idx) {
  idx += KOOSAGA_SZ;
  while(idx) {
    koosagatree[idx] = true;
    idx /= 2;
  }
}
bool qry(int lhs, int rhs) {
  lhs += KOOSAGA_SZ;
  rhs += KOOSAGA_SZ;
  while(lhs <= rhs) {
    if(lhs == rhs) return koosagatree[lhs];
    if(lhs%2) if(koosagatree[lhs++]) return true;
    if(rhs%2==0) if(koosagatree[rhs--]) return true;
    lhs /= 2;
    rhs /= 2;
  }
  return false;
}

vector<int> children[KOOSAGA_SZ];
int vertextoedge[KOOSAGA_SZ]; // vertextoedge[i] gives koosaga tree ID for (parent of i, i) edge
int treedepth[KOOSAGA_SZ];
int treetop[KOOSAGA_SZ];
int treesz[KOOSAGA_SZ];
int lca[KOOSAGA_SZ][KOOSAGA_DEPTH];

bool _sort_by_sz(int a, int b) {
  return treesz[a] > treesz[b];
}
void dfsforhld(int curr, int top, int& id) {
  treetop[curr] = top;
  if(sz(children[curr]) == 0) return;
  sort(all(children[curr]), _sort_by_sz);
  vertextoedge[children[curr][0]] = id++;
  dfsforhld(children[curr][0], top, id);
  for(int i = 1; i < sz(children[curr]); i++) {
    vertextoedge[children[curr][i]] = id++;
    dfsforhld(children[curr][i], children[curr][i], id);
  }
}
void dfsforsz(int curr) {
  treesz[curr] = 1;
  for(int out: children[curr]) {
    treedepth[out] = treedepth[curr] + 1;
    dfsforsz(out);
    treesz[curr] += treesz[out];
  }
}

int getlca(int a, int b) {
  if(treedepth[a] < treedepth[b]) swap(a, b);
  for(int d = KOOSAGA_DEPTH-1; d >= 0; d--) {
    if(treedepth[a] - (1<<d) >= treedepth[b]) a = lca[a][d];
  }
  assert(treedepth[a] == treedepth[b]);
  for(int d = KOOSAGA_DEPTH-1; d >= 0; d--) {
    if(lca[a][d] != lca[b][d]) {
      a = lca[a][d];
      b = lca[b][d];
    }
  }
  while(a != b) {
    a = lca[a][0];
    b = lca[b][0];
  }
  return a;
}

bool pathqry(int root, int curr) {
  assert(treedepth[root] <= treedepth[curr]);
  while(treedepth[curr] > treedepth[root]) {
    if(curr == treetop[curr]) {
      if(qry(vertextoedge[curr], vertextoedge[curr])) return false;
      curr = lca[curr][0];
      continue;
    }
    if(treedepth[treetop[curr]] >= treedepth[root]) {
      // go all the way to top[curr]
      int nume = treedepth[curr] - treedepth[treetop[curr]] - 1;
      assert(nume >= 0);
      if(qry(vertextoedge[curr]-nume, vertextoedge[curr])) return false;
      curr = treetop[curr];
      continue;
    }
    // go all the way to root
    int nume = treedepth[curr] - treedepth[root] - 1;
    assert(nume >= 0);
    if(qry(vertextoedge[curr]-nume, vertextoedge[curr])) return false;
    return true;
  }
  return true;
}

bool connected(int a, int b) {
  int r = getlca(a, b);
  return pathqry(r, a) && pathqry(r, b);
}

void solve() {
  int n, q;
  cin >> n >> q;
  for(int i = 2; i <= n; i++) {
    cin >> lca[i][0];
    children[lca[i][0]].push_back(i);
  }
  dfsforsz(1);
  for(int d = 1; d < KOOSAGA_DEPTH; d++) {
    for(int i = 1; i <= n; i++) {
      lca[i][d] = lca[lca[i][d-1]][d-1];
    }
  }
  {
    int id = 0;
    dfsforhld(1, 1, id);
  }
  while(q--) {
    int a, b, t;
    cin >> a >> b >> t;
    if(connected(a, b)) {
      cout << "YES\n";
      if(t==1) upd(vertextoedge[a]);
    }
    else {
      cout << "NO\n";
      if(t==1) upd(vertextoedge[b]);
    }
  }
}
// are there edge cases (N=1?)
// are array sizes proper (scaled by proper constant, for example 2* for koosaga tree)
// integer overflow?
// DS reset properly between test cases

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL); cout.tie(NULL);
  solve();
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6912 KB Output is correct
2 Correct 8 ms 6784 KB Output is correct
3 Correct 8 ms 6784 KB Output is correct
4 Correct 9 ms 6784 KB Output is correct
5 Correct 8 ms 6784 KB Output is correct
6 Correct 9 ms 6784 KB Output is correct
7 Correct 8 ms 6784 KB Output is correct
8 Correct 9 ms 6784 KB Output is correct
9 Correct 8 ms 6784 KB Output is correct
10 Correct 8 ms 6784 KB Output is correct

Subtask #2
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6912 KB Output is correct
2 Correct 8 ms 6784 KB Output is correct
3 Correct 8 ms 6784 KB Output is correct
4 Correct 9 ms 6784 KB Output is correct
5 Correct 8 ms 6784 KB Output is correct
6 Correct 9 ms 6784 KB Output is correct
7 Correct 8 ms 6784 KB Output is correct
8 Correct 9 ms 6784 KB Output is correct
9 Correct 8 ms 6784 KB Output is correct
10 Correct 8 ms 6784 KB Output is correct
11 Correct 10 ms 6656 KB Output is correct
12 Correct 9 ms 6656 KB Output is correct
13 Correct 9 ms 6656 KB Output is correct
14 Correct 8 ms 6656 KB Output is correct
15 Correct 9 ms 6784 KB Output is correct
16 Incorrect 9 ms 6656 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #3
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6912 KB Output is correct
2 Correct 8 ms 6784 KB Output is correct
3 Correct 8 ms 6784 KB Output is correct
4 Correct 9 ms 6784 KB Output is correct
5 Correct 8 ms 6784 KB Output is correct
6 Correct 9 ms 6784 KB Output is correct
7 Correct 8 ms 6784 KB Output is correct
8 Correct 9 ms 6784 KB Output is correct
9 Correct 8 ms 6784 KB Output is correct
10 Correct 8 ms 6784 KB Output is correct
11 Correct 10 ms 6656 KB Output is correct
12 Correct 9 ms 6656 KB Output is correct
13 Correct 9 ms 6656 KB Output is correct
14 Correct 8 ms 6656 KB Output is correct
15 Correct 9 ms 6784 KB Output is correct
16 Incorrect 9 ms 6656 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6912 KB Output is correct
2 Correct 8 ms 6784 KB Output is correct
3 Correct 8 ms 6784 KB Output is correct
4 Correct 9 ms 6784 KB Output is correct
5 Correct 8 ms 6784 KB Output is correct
6 Correct 9 ms 6784 KB Output is correct
7 Correct 8 ms 6784 KB Output is correct
8 Correct 9 ms 6784 KB Output is correct
9 Correct 8 ms 6784 KB Output is correct
10 Correct 8 ms 6784 KB Output is correct
11 Correct 497 ms 50984 KB Output is correct
12 Correct 473 ms 50936 KB Output is correct
13 Correct 463 ms 51192 KB Output is correct
14 Correct 454 ms 50956 KB Output is correct
15 Correct 455 ms 51024 KB Output is correct
16 Correct 457 ms 51064 KB Output is correct
17 Incorrect 339 ms 51448 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #5
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 6912 KB Output is correct
2 Correct 8 ms 6784 KB Output is correct
3 Correct 8 ms 6784 KB Output is correct
4 Correct 9 ms 6784 KB Output is correct
5 Correct 8 ms 6784 KB Output is correct
6 Correct 9 ms 6784 KB Output is correct
7 Correct 8 ms 6784 KB Output is correct
8 Correct 9 ms 6784 KB Output is correct
9 Correct 8 ms 6784 KB Output is correct
10 Correct 8 ms 6784 KB Output is correct
11 Correct 10 ms 6656 KB Output is correct
12 Correct 9 ms 6656 KB Output is correct
13 Correct 9 ms 6656 KB Output is correct
14 Correct 8 ms 6656 KB Output is correct
15 Correct 9 ms 6784 KB Output is correct
16 Incorrect 9 ms 6656 KB Output isn't correct
17 Halted 0 ms 0 KB -