Submission #486214

#	Time	Username	Problem	Language	Result	Execution time	Memory
486214		SirCovidThe19th	Birthday gift (IZhO18_treearray)	C++17	0 / 100	30 ms	48076 KiB

treearray

#include <bits/stdc++.h>
using namespace std;

#define FOR(i, x, y) for (int i = x; i < y; i++)

const int mx = 2e5 + 5, ml = 18;

int n, m, q, up[mx][ml], dep[mx], A[mx], L[mx]; 
vector<int> adj[mx]; set<int> posA[mx], posL[mx]; 

void dfs(int cur){
    FOR(i, 1, ml) up[cur][i] = up[up[cur][i - 1]][i - 1];
    for (int to : adj[cur]) if (to != up[cur][0]){
        up[to][0] = cur; dep[to] = dep[cur] + 1;
        dfs(to);
    }
}
int lca(int a, int b){
    if (dep[a] < dep[b]) swap(a, b);
    int dif = dep[a] - dep[b];
    FOR(i, 0, 18) if ((dif >> i) % 2) a = up[a][i];
    if (a == b) return a;
    for (int i = 17; ~i; i--) if (up[a][i] != up[b][i]) a = up[a][i], b = up[b][i];
    return up[a][0];
}
void upd(int i, int v){
    posA[A[i]].erase(i); A[i] = v; posA[A[i]].insert(i);

    posL[L[i - 1]].erase(i - 1); posL[L[i]].erase(i);
    L[i - 1] = lca(A[i - 1], A[i]); L[i] = lca(A[i], A[i + 1]);
    posL[L[i - 1]].insert(i - 1); posL[L[i]].insert(i);
}
bool solve(int l, int r, int v){
    auto itA = posA[v].lower_bound(l);
    auto itL = posL[v].lower_bound(l);

    if (itA != posA[v].end() and *itA <= r) cout<<*itA<<" "<<*itA<<"\n";
    else if (itL != posL[v].end() and *itL < r) cout<<*itL<<" "<<*itL + 1<<"\n";
    else cout<<"-1 -1"<<"\n";
}
int main(){
    cin >> n >> m >> q;
    FOR(i, 1, n){
        int a, b; cin >> a >> b;
        adj[a].push_back(b); adj[b].push_back(a);
    }
    dfs(1);
    FOR(i, 1, m + 1){ int v; cin >> v; upd(i, v); }
    while (q--){
        int t; cin >> t;
        if (t == 1){ int a, v; cin >> a >> v; upd(a, v); }
        else{ int l, r, v; cin >> l >> r >> v; solve(l, r, v); }
    }
}

Compilation message (stderr)

treearray.cpp: In function 'bool solve(int, int, int)':
treearray.cpp:40:1: warning: no return statement in function returning non-void [-Wreturn-type]
   40 | }
      | ^

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