Submission #1086276

#	Time	Username	Problem	Language	Result	Execution time	Memory
1086276		vjudge1	Magic Tree (CEOI19_magictree)	C++14	3 / 100	72 ms	13292 KiB

magictree

#include<bits/stdc++.h>
using namespace std;

#define NAME ""
#define ll long long
#define pii pair < int , int >
#define fi first
#define se second
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i ++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i --)
#define REP(i, n) for (int i = 0, _n = (n); i < _n; i ++)
#define bit(x, i) (((x) >> (i)) & 1ll)
#define mask(x) (1ll << (x))
#define mem(f, x) memset(f, x, sizeof(f))
#define sz(x) (int32_t) (x.size())

const int nmax = 1e5;
int in[nmax + 5], out[nmax + 5], timer = 0;
vector < int > adj[nmax + 5];
vector < pii > fruits[nmax + 5];

struct SegTree {
  int n;
  bool del[nmax * 4 + 5];
  ll b[nmax * 4 + 5];

  void init(int _n) {
    n = _n;
  }

  void down(int id) {
    if (!del[id]) {
      return;
    }

    del[id << 1] = 1;
    del[id << 1 | 1] = 1;

    b[id << 1] = 0;
    b[id << 1 | 1] = 0;

    del[id] = 0;
  }

  void update(int id, int l, int r, int u, int v, int val) {
    if (l > v || u > r) {
      return;
    }

    if (u <= l && r <= v) {
      if (val != -1) {
        b[id] = val;
      }
      else {
        del[id] = 1;
        b[id] = 0;
      }
      return;
    }

    down(id);

    int mid = (l + r) >> 1;
    update(id << 1, l, mid, u, v, val);
    update(id << 1 | 1, mid + 1, r, u, v, val);

    b[id] = b[id << 1] + b[id << 1 | 1];
  }

  ll get(int id, int l, int r, int u, int v) {
    if (u > r || l > v) {
      return 0;
    }

    if (u <= l && r <= v) {
      return b[id];
    }
    down(id);

    int mid = (l + r) >> 1;
    return get(id << 1, l, mid, u, v) + get(id << 1 | 1, mid + 1, r, u, v);
  }

  void update(int l, int r, int val) {
    update(1, 1, n, l, r, val);
//    cout << l << " " << r << " " << val << "\n";
  }

  ll get(int l, int r) {
    return get(1, 1, n, l, r);
  }
}seg;

void dfs(int i) {
  in[i] = ++ timer;

  for (auto x: adj[i]) {
    dfs(x);
  }

  out[i] = timer;
}

signed main() {
  if (fopen(NAME".inp", "r")) {
    freopen(NAME".inp", "r", stdin);
    freopen(NAME".out", "w", stdout);
  }
  cin.tie(0)->sync_with_stdio(0);

  int n, m, k;
  cin >> n >> m >> k;
  seg.init(n);

  FOR(i, 2, n) {
    int p;
    cin >> p;
    adj[p].push_back(i);
  }
  dfs(1);

  for (; m --;) {
    int v, d, w;
    cin >> v >> d >> w;
    fruits[d].push_back({v, w});
  }

  FORD(i, k, 1) {
    sort(fruits[i].begin(), fruits[i].end(), [&] (const pii &x, const pii &y) {
      return (in[x.fi] < in[y.fi]);
    });

    for (auto x: fruits[i]) {
      int u = x.fi;
      if (seg.get(in[u], out[u]) <= x.se) {
        seg.update(in[u], out[u], -1);
        seg.update(in[u], in[u], x.se);
      }
    }
  }

  cout << seg.b[1];

  return 0;
}

Compilation message (stderr)

magictree.cpp: In function 'int main()':
magictree.cpp:106:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |     freopen(NAME".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
magictree.cpp:107:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |     freopen(NAME".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 3 / 3
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 16
• Subtask 6: 0 / 13
• Subtask 7: 0 / 22
• Subtask 8: 0 / 17