Submission #1151799

#	Time	Username	Problem	Language	Result	Execution time	Memory
1151799		sofiefu	Inside information (BOI21_servers)	C++20	0 / 100	30 ms	9672 KiB

servers

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define vo vector
#define pb push_back
#define se second
#define fi first
#define all(v) v.begin(), v.end()
typedef vector<int> vi;
typedef pair<int, int> pii;

#define rep(i, a, b) for(int i=(a); i<b; i++)
#define pr1(x) cerr << #x << '=' << x << ' ';
//for google contests
#define umap unordered_map
#define uset unordered_set
#define repd(i, a, b) for(int i=(b-1); i >= a; i--)
void _pr(signed x) {cerr << x;}
void _pr(long long x) {cerr << x;}
void _pr(size_t x) {cerr << x;}
void _pr(string &x) {cerr << x;}
void _pr(double x) {cerr << x;}
void _pr(char x) {cerr << '\'' << x << '\'';}
void _pr(const char* x) {cerr << x;}
void _pr(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V> void _pr(const pair<T, V> &x);
template<typename T, typename V> void _pr(const pair<T, V> &x) {cerr << "\e[95m" << "[ "; _pr(x.first); cerr << ", "; _pr(x.second); cerr << "\e[95m" << ']';}
template<typename T> void _pr(const T &x) {int F=0; cerr << '{'; for(auto &i: x) cerr << (F++ ? ", " : ""), _pr(i); cerr << "\e[91m" << '}';}
template <typename T, typename... V> void _pr(T t, V... v) {_pr(t); if(sizeof...(v)) cerr << ", "; _pr(v...);}
#define pr(x...) cerr << "\e[91m" << __func__ << ':' << __LINE__ << " [" << #x << "] = ["; _pr(x); cerr << "\e[91m" << ']' << "\033[0m"  << endl;
mt19937 mt_rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r){return uniform_int_distribution<int>(l, r)(mt_rng);}

//go for outline with ;, then details
int const inf = 1e18, mxn = 1e5+2e4+5;
int n, q; 
vo<vo<pii>> adj(mxn);
int const mxlog = 25;
int bl[mxn][mxlog], dep[mxn], paredge[mxn];
vo<vi> C;
vo<array<int, 3>> Q;
vi upDecr, upIncr;

void precomp(int at, int p, int depth, int prevedge, int incr, int decr){
    sort(all(adj[at]), greater<>()); // nice properties
    dep[at] = depth; bl[at][0] = p; paredge[at] = prevedge; // what about root
    rep(i, 1, mxlog) bl[at][i] = bl[bl[at][i-1]][i-1];

    upDecr[at] = decr, upIncr[at] = incr;

    for(auto [x, ind]: adj[at]){
        if(x==p) continue;   
        if(prevedge>ind) precomp(x, at, depth+1, ind, incr+1, 1);
        else precomp(x, at, depth+1, ind, 1, decr+1);
    }
}
int LCA(int a, int b){
    if(dep[a] < dep[b]) swap(a, b);

    int d = dep[a]-dep[b];
    rep(i, 0, mxlog){
        if((d>>i) & 1) a = bl[a][i];
    }
    if(a==b) return a;

    repd(i, 0, mxlog){
        if(bl[a][i] != bl[b][i]){
            a = bl[a][i], b = bl[b][i];
        }
    }
    return bl[a][0];
}
int get_lastedge(int v, int d){
    d--;
    rep(i, 0, mxlog){
        if((d>>i) & 1) v = bl[v][i];
    } 
    return paredge[v];
}

int vis[mxn], ans[2*mxn];
int solveQ(int a, int b, int tme){ // solve all queries of type Q
    if(a==b) return 1;
    int lca = LCA(a, b);

    if(upIncr[b]>=dep[b]-dep[lca] && upDecr[a]>=dep[a]-dep[lca]){
        if(a==lca){
            int ind = get_lastedge(b, dep[b]-dep[lca]);
            if(ind<tme) return 1;
        }
        else if(b==lca){
            int ind = paredge[a];
            if(ind<tme) return 1;
        }
        else{
            int indA = get_lastedge(a, dep[a]-dep[lca]), indB = get_lastedge(b, dep[b]-dep[lca]);
            if(indA>indB && paredge[a]<tme) return 1;
        }
    }
    return 0;
}

signed main(){
    cin.tie(0)->sync_with_stdio(0);
    cin>>n>>q;
    upDecr.resize(n); upIncr.resize(n); C.resize(n); Q.resize(n); 

    int timer=0;
    vi queries;
    rep(i, 0, n+q-1){
        char t; int a, b; cin>>t;
        if(t=='S'){
            cin>>a>>b; a--, b--;
            adj[a].pb({b, timer}); adj[b].pb({a, timer}); queries.pb(0);
        }
        else if(t=='Q'){
            cin>>a>>b; a--, b--; //does a store b, 
            Q.pb({a, b, timer});
            queries.pb(1);
        }
        else{
            cin>>a; a--;
            C[a].pb(timer); queries.pb(2);
        }
        timer++;
    }   
    precomp(0, 0, 0, -1, 0, 0);
    vi ansQ(n+q), ansC(n+q);
    for(auto [a, b, tme]: Q) ansQ[tme] = solveQ(a, b, tme);

    rep(i, 0, n+q-1){
        int type = queries[i];
        if(type==1) cout << (ansQ[i] ? "yes" : "no") << "\n";
        else cout << "-1\n";
    }
}

• Subtask 1-1: 0 / 2
• Subtask 1-2: 0 / 3
• Subtask 2-1: 0 / 2
• Subtask 2-2: 0 / 3
• Subtask 3-1: 0 / 5
• Subtask 3-2: 0 / 5
• Subtask 4-1: 0 / 10
• Subtask 4-2: 0 / 10
• Subtask 5-1: 0 / 12
• Subtask 5-2: 0 / 13
• Subtask 6-1: 0 / 17
• Subtask 6-2: 0 / 18