Submission #1095829

#	Time	Username	Problem	Language	Result	Execution time	Memory
1095829		cpptowin	Pastiri (COI20_pastiri)	C++17	100 / 100	387 ms	137552 KiB

pastiri

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define inf (int)1e18
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1 << j))
#define onbit(i, j) (i | (1 << j))
#define vi vector<int>
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
int n, k;
vi ke[maxn], adj[maxn], save;
pii edge[maxn];
int h[maxn], d[maxn], a[maxn];
bool sheep[maxn], vis[maxn];
void bfs()
{
    memset(d,-1,sizeof d);
    queue<int> q;
    fo(i, 1, n) if (sheep[i])
    {
        q.push(i), d[i] = 0;
    }
    while (q.size())
    {
        int u = q.front();
        q.pop();
        for (int v : ke[u])
        {
            if (d[v] == -1)
            {
                d[v] = d[u] + 1;
                q.push(v);
            }
        }
    }
}
void dfs(int u, int par = 0, int now = 0)
{
    if (d[now] + h[now] < d[u] + h[u])
        now = u;
    a[u] = now;
    for (int v : ke[u])
    {
        if (v == par)
            continue;
        h[v] = h[u] + 1;
        dfs(v, u, now);
    }
}
void dfs1(int u, int par = 0)
{
    vis[u] = 1;
    for (int v : ke[u]) if(d[u] == d[v] + 1)
    {
        if (vis[v])
            continue;
        dfs1(v, u);
    }
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> k;
    fo(i, 1, n - 1)
    {
        int u, v;
        cin >> u >> v;
        ke[u].pb(v);
        ke[v].pb(u);
        edge[i] = {u, v};
    }
    fo(i, 1, k)
    {
        int x;
        cin >> x;
        sheep[x] = 1;
    }
    int node = 1;
    fo(i, 1, n) if (sheep[i])
    {
        node = i;
        break;
    }
    bfs();
    dfs(node);
    a[node] = node;
    fo(i, 1, n) if (sheep[i]) adj[h[i]].pb(i);
    fod(i, n, 0) for (int it : adj[i]) save.pb(it);
    vi ans;
    for (int it : save) if(!vis[it])
    {
        ans.pb(a[it]);
        dfs1(a[it]);
    }
    cout << ans.size();
    en;
    for (int it : ans)
        cout << it << ' ';
    en;
}

Compilation message (stderr)

pastiri.cpp:91:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   91 | main()
      | ^~~~
pastiri.cpp: In function 'int main()':
pastiri.cpp:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
pastiri.cpp:97:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 18 / 18
• Subtask 3: 23 / 23
• Subtask 4: 51 / 51