Submission #495845

#	Time	Username	Problem	Language	Result	Execution time	Memory
495845		Nalrimet	Segments (IZhO18_segments)	C++17	0 / 100	45 ms	65540 KiB

segments

//#pragma GCC target("avx2")
//#pragma GCC optimization("O3")
//#pragma GCC optimization("unroll-loops")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second

using namespace std;

const int N = 2 * 1e5 + 5;
const int MOD = 1e9 + 7;
const int K = 18;

int n, m, q, a[N], par[N][K], h[N];
vector<int> g[N];
pair<int, int> ans;

void dfs(int v, int pr){
	par[v][0] = pr;

	for(int to : g[v]){
		if(to != pr){
			h[to] = h[v] + 1;
			dfs(to, v);
		}
	}
}

bool bit(int x, int p){
	return x & (1 << p);
}

int lift(int v, int k){
	for(int i = 0; i < K; i++){
		if (bit(k, i)) {
			v = par[v][i];
		}
	}
	return v;
}

int lca(int a, int b){
	if(h[a] < h[b]){
		swap(a, b);
	}
	a = lift(a, h[a] - h[b]);
	if(a == b){
		return a;
	}
	for(int i = K - 1; i >= 0; --i){
		if(par[a][i] != par[b][i]){
			a = par[a][i];
			b = par[b][i];
		}
	}
	return par[a][0];
}


int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

	cin >> n >> m >> q;

	for(int i = 1, u, v; i < n; i++){
		cin >> u >> v;
		g[u].pb(v);
		g[v].pb(u);
	}

    dfs(1, 1);

    for(int i = 1; i < K; i++){
    	for(int v = 1; v <= n; v++){
    		par[v][i] = par[par[v][i - 1]][i - 1];
    	}
    }

    for(int i = 1; i <= m; ++i){
        cin >> a[i];
    }

    int pos, v, l, r, typ;

	for (int i = 1; i <= q; i++) {
        cin >> typ;
        if(typ == 1){
            cin >> pos >> v;
            a[pos] = v;
        }
        else{
            cin >> l >> r >> v;
            ans = {-1, -1};
            for(int i = l; i <= r; ++i){
                if(a[i] == v){
                    ans = {i, i};
                    break;
                }
                if(i + 1 <= r && lca(a[i], a[i + 1]) == v){
                    ans = {i, i + 1};
                    break;
                }
            }
            cout << ans.F << ' ' << ans.S << '\n';
        }
	}

	return 0;
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 15
• Subtask 3: 0 / 16
• Subtask 4: 0 / 17
• Subtask 5: 0 / 20
• Subtask 6: 0 / 25