Submission #1007741

#	Time	Username	Problem	Language	Result	Execution time	Memory
1007741		ByeWorld	Birthday gift (IZhO18_treearray)	C++14	56 / 100	4070 ms	57484 KiB

treearray

#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 2e5+10;
const int MAXA = 2e3+10;
const int INF = 1e18+10;
const int LOG = 19;
const int MOD = 1e9+7;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};

int n, m, q;
int a[MAXN];
vector <int> adj[MAXN];
bool b[MAXN];
int anc[MAXN][LOG+5], dep[MAXN];

void dfs(int nw, int par){
    anc[nw][0] = par; dep[nw] = dep[par]+1;
    for(auto nx : adj[nw]){
        if(nx==par) continue;
        dfs(nx, nw);
    }
}
int LCA(int x, int y){
    if(dep[x] > dep[y]) swap(x, y);
    for(int i=LOG-1; i>=0; i--){
        if(dep[anc[y][i]] >= dep[x])
            y = anc[y][i];
    }
    if(x==y) return x;
    for(int i=LOG-1; i>=0; i--){
        if(anc[x][i] != anc[y][i]){
            x = anc[x][i]; y = anc[y][i];
        }
    }
    return anc[x][0];
}
signed main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n >> m >> q;
    for(int i=1; i<=n-1; i++){
        int x, y; cin >> x >> y;
        adj[x].pb(y); adj[y].pb(x);
    }
    dfs(1, 0);
    for(int j=1; j<LOG; j++)
        for(int i=1; i<=n; i++)
            anc[i][j] = anc[anc[i][j-1]][j-1];

    for(int i=1; i<=m; i++) cin >> a[i];
    for(int xx=1; xx<=q; xx++){
        int ty; cin >> ty;
        if(ty==1){
            int pos, x; cin >> pos >> x;
            a[pos] = x;
            continue;
        }
        int l, r, x; cin >> l >> r >> x;
        for(int i=l; i<=r; i++){
            if(LCA(a[i], x) == x) b[i] = 1;
            else b[i] = 0;
        }
        bool done = 0;
        for(int i=l; i<=r; i++){
            if(!b[i]) continue;
            int las = i, nw = a[i];
            while(i+1<=r && b[i+1]){
                i++; nw = LCA(nw, a[i]);
            }
            if(nw == x){
                done = 1;
                cout << las << ' ' << i << '\n';
                break;
            }
        }
        if(!done) cout << "-1 -1\n"; 
    }
}

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