Submission #853679

#	Time	Username	Problem	Language	Result	Execution time	Memory
853679		anha3k25cvp	Birthday gift (IZhO18_treearray)	C++14	100 / 100	862 ms	77120 KiB

treearray

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define dl double
#define st first
#define nd second
#define II pair <int, int>

using namespace std;

const int N = 5 + 1e5;
const int inf = 7 + 1e9;

int logn;
vector <int> h;
vector <vector <int>> adj, p;

void dfs(int u) {
    for (int v : adj[u])
        if (!h[v]) {
            p[0][v] = u;
            h[v] = h[u] + 1;
            dfs(v);
        }
}

int lca(int u, int v) {
    if (h[u] < h[v])
        swap(u, v);
    for (int si = h[u] - h[v]; si > 0; si ^= si & -si) {
        int i = __builtin_ctz(si & -si);
        u = p[i][u];
    }
    if (u == v)
        return u;
    for (int i = logn - 1; i >= 0; i --)
        if (p[i][u] != p[i][v]) {
            u = p[i][u];
            v = p[i][v];
        }
    return p[0][u];
}

int main() {
#define TASKNAME ""
    ios_base :: sync_with_stdio (0);
    cin.tie (0);
    if ( fopen( TASKNAME".inp", "r" ) ) {
        freopen (TASKNAME".inp", "r", stdin);
        freopen (TASKNAME".out", "w", stdout);
    }
    int n, m, t;
    cin >> n >> m >> t;
    adj.resize(n + 1);
    for (int i = 1; i < n; i ++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (logn = 1; 1 << logn <= n; logn ++);
    p.assign(logn, vector <int> (n + 1, 0));
    h.assign(n + 1, 0);
    h[1] = 1;
    dfs(1);
    for (int i = 1; i < logn; i ++)
        for (int u = 1; u <= n; u ++)
            p[i][u] = p[i - 1][p[i - 1][u]];
    vector <int> a(m + 1, 0), b(m, 0);
    vector <set <int>> q(n + 1), g(n + 1);
    for (int i = 1; i <= m; i ++) {
        cin >> a[i];
        g[a[i]].insert(i);
        if (i > 1) {
            b[i - 1] = lca(a[i - 1], a[i]);
            q[b[i - 1]].insert(i - 1);
        }
    }
    while (t --) {
        int type;
        cin >> type;
        if (type == 1) {
            int pos, val;
            cin >> pos >> val;
            g[a[pos]].erase(pos);
            a[pos] = val;
            g[val].insert(pos);
            if (pos > 1) {
                q[b[pos - 1]].erase(pos - 1);
                b[pos - 1] = lca(a[pos - 1], a[pos]);
                q[b[pos - 1]].insert(pos - 1);
            }
            if (pos < m) {
                q[b[pos]].erase(pos);
                b[pos] = lca(a[pos], a[pos + 1]);
                q[b[pos]].insert(pos);
            }
        }
        else {
            int u, v, val;
            cin >> u >> v >> val;
            auto it = q[val].lower_bound(u), it1 = g[val].lower_bound(u);
            if (it != q[val].end() &&  *it < v)
                cout << *it << ' ' << *it + 1 << '\n';
            else if (it1 != g[val].end() && *it1 <= v)
                cout << *it1 << ' ' << *it1 << '\n';
            else
                cout << "-1 -1\n";
        }
    }
    return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:49:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |         freopen (TASKNAME".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:50:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         freopen (TASKNAME".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 44 / 44