Submission #619966

#	Time	Username	Problem	Language	Result	Execution time	Memory
619966		welleyth	Min-max tree (BOI18_minmaxtree)	C++17	0 / 100	1090 ms	25024 KiB

minmaxtree

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;

#define int long long
#define mp make_pair
#define pb push_back

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx2")

constexpr int INF = (int)2e9;
constexpr int N = (int)7e4 + 111;
constexpr int md = (int)998244353;
constexpr int mdPower = (int)1e9+7 - 1;
constexpr double eps = 1e-7;

typedef __int128 _uint;
typedef long long ll;

mt19937_64 rnd(time(nullptr));

void add(int& a,int b){
    a += b; if(a >= md) a -= md;
}
void sub(int& a,int b){
    a -= b; while(a < 0) a += md;
}
void add(__int128& a,int b){
    a += b;
}
void sub(__int128& a,int b){
    a -= b;
}

int bpow(int a,int b){
    if(b == 0)
        return 1;
    if(b % 2 == 0){
        int t = bpow(a,b>>1);
        return 1ll*t*t%md;
    }
    return 1ll * a*bpow(a,b-1) % md;
}

int inv(int a){
    return bpow(a,md-2);
}

//int fac[N],invfac[N];
//
//void init(){
//    fac[0] = 1;
//    for(int i = 1; i < N; i++){
//        fac[i] = (fac[i-1] * i) % md;
//    }
//    invfac[N-1] = inv(fac[N-1]);
//    for(int i = N-2; i >= 0; i--){
//        invfac[i] = (invfac[i+1] * (i+1))%md;
//    }
//    return;
//}
//
//int C(int n,int k){
//    if(k > n)
//        return 0;
//    return fac[n] * invfac[k] % md * invfac[n-k] % md;
//}
//
//int A(int n,int k){
//    if(k > n)
//        return 0;
//    return fac[n] * invfac[n-k] % md;
//

vector<int> g[N];
int p[N];
int up[20][N];
int tin[N],tout[N];
int timer = 0;
int d[N];

void dfs(int v,int pr){
    p[v] = pr;
    tin[v] = timer++;
    up[0][v] = pr;
    for(int i = 1; i < 20; i++){
        up[i][v] = up[i-1][up[i-1][v]];
    }
    for(auto& to : g[v]){
        if(to == pr)
            continue;
        d[to] = d[v] + 1;
        dfs(to,v);
    }
    tout[v] = timer++;
    return;
}

bool upper(int a,int b){
    return tin[a] <= tin[b] && tout[a] >= tout[b];
}

int lca(int a,int b){
    if(upper(a,b)) return a;
    if(upper(b,a)) return b;
    for(int i = 19; i >= 0; i--){
        if(!upper(up[i][a],b))
            a = up[i][a];
    }
    return up[0][a];
}

int L[N],R[N];

void solve(){
    int n;
    cin >> n;

    for(int i = 1; i < n; i++){
        int a,b;
        cin >> a >> b;
        g[a].pb(b);
        g[b].pb(a);
    }
    for(int i = 1; i <= n; i++){
        L[i] = -1;
        R[i] = INF;
    }

    dfs(1,1);

    int q;
    cin >> q;

    for(int i = 0; i < q; i++){
        char ch;
        cin >> ch;
        int a,b;
        cin >> a >> b;
        int z;
        cin >> z;

        int LCA = lca(a,b);
        while(a != LCA){
            if(ch == 'M'){
                R[a] = min(R[a],z);
            } else {
                L[a] = min(L[a],z);
            }
            a = p[a];
        }
        while(b != LCA){
            if(ch == 'M'){
                R[b] = min(R[b],z);
            } else {
                L[b] = min(L[b],z);
            }
            b = p[b];
        }
    }

    vector<pair<int,int>> ans;

    for(int i = 2; i <= n; i++){
        int x;
        if(L[i] == -1 && R[i] == INF)
            x = 0;
        else if(L[i] == -1)
            x = R[i];
        else if(R[i] == INF)
            x = L[i];
        else
            x = (d[i] % 2 == 0 ? L[i] : R[i]);
        cout << i << " " << p[i] << " " << x << "\n";
    }

    return;
}

signed main(){
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
    int tests = 1;
//    cin >> tests;
    for(int test = 1; test <= tests; test++){
//        cerr << "test = " << test << "\n";
        solve();
    }
    return 0;
}
/**
x2 x1 x0

[x2+2*x1+x0] [x1+x0] [x0]

1 0 0
2 1 0
1 1 1

1 0 0
-2 1 0
1 -1 1

**/

• Subtask 1: 0 / 7
• Subtask 2: 0 / 22
• Subtask 3: 0 / 29
• Subtask 4: 0 / 42