Submission #1123232

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123232		gdragon	Birthday gift (IZhO18_treearray)	C++20	56 / 100	128 ms	13128 KiB

treearray

#include <bits/stdc++.h>
using namespace std;
#define TASK "long"
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define GETBIT(mask, i) ((mask) >> (i) & 1)
#define MASK(i) ((1LL) << (i))
#define SZ(x) ((int)(x).size())
#define mp make_pair
#define CNTBIT(mask) __builtin_popcount(mask)
template<class X, class Y> bool maximize(X &x, Y y){ if (x < y) {x = y; return true;} return false;};
template<class X, class Y> bool minimize(X &x, Y y){ if (x > y) {x = y; return true;} return false;};
typedef pair<int, int> ii;
const int N = 1e5 + 5;
const int inf = 1e9 + 7;
const long long INF = (long long)1e18 + 7;
const int mod = 1e9 + 7;
void add(int &x, int y) {x += y; if (x >= mod) x -= mod;}
void sub(int &x, int y) {x -= y; if (x < 0) x += mod;}
int mul(int x, int y) {return 1LL * x * y % mod;}
// -----------------------------------------//
const int LOG = 17;
int n, m, q;
int a[N], par[N][LOG + 2], high[N], tin[N], tout[N];
vector<int> adj[N];
void read() {
    cin >> n >> m >> q;
    for(int i = 1; i < n; i++) {
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for(int i = 1; i <= m; i++) cin >> a[i];
}
int timer = 0;
void dfs(int u) {
    tin[u] = ++timer;
    for(int v: adj[u]) if (v != par[u][0]) {
        high[v] = high[u] + 1;
        par[v][0] = u;
        dfs(v);
    }
    tout[u] = timer;
}
bool isChild(int u, int p) {
    return tin[p] <= tin[u] && tin[u] <= tout[p];
}
int LCA(int u, int v) {
    if (u == 0 || v == 0) return u + v;
    if (high[u] < high[v]) swap(u, v);
    int d = high[u] - high[v];
    for(int i = LOG; i >= 0; i--) if (d & (1 << i)) u = par[u][i];
    if (u == v) return u;
    for(int i = LOG; i >= 0; i--) if (par[u][i] != par[v][i]) {
        u = par[u][i];
        v = par[v][i];
    } 
    return par[u][0];
}
void sub2() {
    dfs(1);
    for(int j = 1; j <= LOG; j++) {
        for(int i = 1; i <= n; i++) {
            par[i][j] = par[par[i][j - 1]][j - 1];
        }
    }
    while(q--) {
        int type; cin >> type;
        if (type == 1) {
            int pos, v; cin >> pos >> v;
            a[pos] = v;
        }
        else {
            int l, r, p; cin >> l >> r >> p;
            int sta = 0, lca = 0;
            bool ok = 0;
            for(int i = l; i <= r; i++) {
                if (isChild(a[i], p)) {
                    sta = (sta == 0 ? i : sta);
                    lca = LCA(lca, a[i]);
                    if (lca == p) {
                        ok = 1;
                        cout << sta << ' ' << i << endl;
                        break;
                    }
                } 
                else {
                    lca = 0;
                    sta = 0;
                }
            }
            if (!ok) cout << -1 << ' ' << -1 << endl;
        }
    }
}
void solve() {
    sub2();
}
signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    int test = 1;
    // cin >> test;
    while(test--) {
        read();
        solve();
    }
    return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:105:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:106:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 0 / 44