Submission #831465

#	Time	Username	Problem	Language	Result	Execution time	Memory
831465		Cookie	Birthday gift (IZhO18_treearray)	C++14	56 / 100	4037 ms	36904 KiB

treearray

#include<bits/stdc++.h>
#include<fstream>
#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
//ifstream fin("FEEDING.INP");
//ofstream fout("FEEDING.OUT");
#define sz(a) (int)a.size()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const int base = 74;
const int mxn = 2e5 + 5;
int n, m, q;
vt<int>adj[mxn + 1];
int dep[mxn + 1], up[mxn + 1][18], a[mxn + 1], tin[mxn + 1], tt = 0, tout[mxn + 1], inf = 1e9;
void dfs(int s, int pre){
    tin[s] = ++tt;
    for(auto i: adj[s]){
        if(i != pre){
            dep[i] = dep[s] + 1;
            dfs(i, s); up[i][0] = s; 
        }
    }
    tout[s] = tt;
}
int lca(int u, int v){
    if(dep[u] < dep[v])swap(u, v);
    int k = dep[u] - dep[v];
    forr(i, 0, 18){
        if(k & (1 << i)){
            u = up[u][i];
        }
    }
    if(u == v)return(u);
    dorr(i, 17, 0){
        if(up[u][i] != up[v][i]){
            u = up[u][i]; v = up[v][i];
        }
    }
    return(up[u][0]);
}
signed main()
{
     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> m >> q;
    forr(i, 1, n){
        int u, v; cin >> u >> v;
        adj[u].pb(v); adj[v].pb(u);
    }
    for(int i = 1; i <= m; i++)cin >> a[i];
    dfs(1, -1);
    forr(i, 1, 18){
        for(int j = 1; j <= n; j++){
            up[j][i] = up[up[j][i - 1]][i - 1];
        }
    }
    while(q--){
        int idq; cin >> idq;
        if(idq == 1){
            int id, x; cin >> id >> x; a[id] = x;
        }else{
            int l, r, v; cin >> l >> r >> v;
            int last = l, mn = inf, mx = -1, valmn = -1, valmx = -1;
            bool ok = 0;
            for(int i = l; i <= r; i++){
                if(tin[a[i]] < tin[v] | tin[a[i]] > tout[v]){
                    mn = inf; mx = -1; valmn = -1; valmx = -1;
                    continue;
                }else{
                    if(tin[a[i]] < mn){
                        mn = tin[a[i]]; valmn = i;
                    }if(tin[a[i]] > mx){
                        mx = tin[a[i]]; valmx = i;
                    }
                    int cand = lca(a[valmn], a[valmx]);
                    if(cand == v){
                        cout << min(valmn, valmx) << " " << max(valmn, valmx) << "\n";
                        ok = 1;
                        break;
                    }
                }
            }
            if(!ok)cout << -1 << " " << -1 << "\n";
        }
    }
    return(0);
}

Compilation message (stderr)

treearray.cpp: In function 'int main()':
treearray.cpp:75:30: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   75 |                 if(tin[a[i]] < tin[v] | tin[a[i]] > tout[v]){
      |                    ~~~~~~~~~~^~~~~~~~
treearray.cpp:72:17: warning: unused variable 'last' [-Wunused-variable]
   72 |             int last = l, mn = inf, mx = -1, valmn = -1, valmx = -1;
      |                 ^~~~

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