Submission #331458

#	Time	Username	Problem	Language	Result	Execution time	Memory
331458		BeanZ	Uzastopni (COCI15_uzastopni)	C++14	160 / 160	95 ms	29992 KiB

uzastopni

// I_Love_LPL
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 1e4 + 5;
const int mod = 1e9 + 7;
const int lim = 100;
bitset<101> bit[N][105];
vector<ll> node[N], d[101];
vector<pair<ll, ll>> q[N];
ll a[N];

/*
  Sol: Goi q[u] la tat ca cac cap (l, r) sao cho subtree cua u co the lam dc 1 doan (l, r)
  Goi bit[u][l] la mot mang bool neu bit thu r cua mang nay bat tuc la doan (l, r) trong subtree u co the lam dc
  bit[u][l] dc tinh bang cach xet toan bo cac node con cua u
  Ta se tinh dc q[u] cua tung node con cua u
  Khi do ta xem tat ca cac cap (lf, rt) ma lf == l
  {
      bit[u][l] |= bit[u][r + 1] (de tranh bi lay 2 joke chung nen se lay bit tu r + 1 tro di)
      bit[u][l].set(r) (tu cai dat cho no rang (l, r) dc)
  }
  Sau do voi moi doan (l, r) dc tao thanh ta kiem tra xem l <= a[u] && r >= a[u] ko roi them no vao q[u]
  de tinh cho cha cua u.
*/

void dfs(ll u){
    for (auto j : node[u]) dfs(j);
    for (int i = 1; i <= lim; i++) d[i].clear();
    for (auto j : node[u]){
        for (auto t : q[j]){
            d[t.first].push_back(t.second);
        }
    }
    for (int i = lim; i >= 1; i--){
        if (a[u] == i){
            bit[u][i].set(i);
            bit[u][i] |= bit[u][i + 1];
        } else {
            for (auto r : d[i]){
                if (r < a[u] || i > a[u]){
                    bit[u][i].set(r);
                    bit[u][i] |= bit[u][r + 1];
                }
            }
        }
        for (int r = lim; r >= i; r--){
            if (bit[u][i][r] && a[u] >= i && a[u] <= r){
                q[u].push_back({i, r});
            }
        }
    }
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("A.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n;
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i < n; i++){
        ll u, v;
        cin >> u >> v;
        node[u].push_back(v);
    }
    dfs(1);
    cout << q[1].size();
}
/*
*/

Compilation message (stderr)

uzastopni.cpp: In function 'int main()':
uzastopni.cpp:59:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   59 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
uzastopni.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   60 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 160 / 160