Submission #1123220

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123220		gdragon	Birthday gift (IZhO18_treearray)	C++20	0 / 100	4 ms	2628 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], high[N];
int tin[N], tout[N];
pair<int, int> euler[2 * N], par[N][LOG + 2];
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, int p) {
    tin[u] = ++timer;
    euler[timer] = {high[u], u};
    for(int v: adj[u]) if (v != p) {
        high[v] = high[u] + 1;
        dfs(v, u);
        euler[++timer] = {high[u], u};
    }
    tout[u] = timer;
}
int LCA(int u, int v) {
    if (u > v) swap(u, v);
    int k = log2(v - u + 1);
    return min(par[u][k], par[u + MASK(k) - 1][k]).se;
}
int getLCA(int u, int v) {
    return LCA(tin[u], tin[v]);
}
void sub2() {
    dfs(1, -1);
    for(int i = 1; i <= timer; i++) par[i][0] = euler[i];
    for(int j = 1; j <= LOG; j++) {
        for(int i = 1; i + MASK(j) - 1 <= timer; i++) {
            par[i][j] = min(par[i][j - 1], par[i + MASK(j - 1)][j - 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, v; cin >> l >> r >> v;
            bool ok = 0;
            for(int i = l; i <= r && (!ok); i++) {
                if (a[i] == v) {
                    cout << i << ' ' << i << endl;
                    ok = 1;
                    break;
                }
                int lca = a[i];
                for(int j = i + 1; j <= r; j++) {
                    lca = getLCA(lca, a[j]);
                    if (lca == v) {
                        ok = 1;
                        cout << i << ' ' << j << endl;
                        break;
                    }
                }
            }
            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:107:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:108:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  108 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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