Submission #1142816

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142816		steveonalex	Closing Time (IOI23_closing)	C++20	100 / 100	173 ms	45424 KiB

closing

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

#include "closing.h"

const int N = 2e5 + 69;
const ll INF = 1e18 + 69;
int n;
vector<pair<int, int>> graph[N];
int parent[N];
ll dis[N];

void reset(){
    for(int i = 0; i < n; ++i) graph[i].clear();
}

void dfs(int u, int p){
    parent[u] = p;
    for(pair<int, int> v: graph[u]) if (v.first != p){
        dis[v.first] = dis[u] + v.second;
        dfs(v.first, u);
    }
}

int greedy1(vector<ll> dis1, vector<ll> dis2, ll k){
    int n = dis1.size();
    vector<ll> dis(n);
    for(int i = 0; i < n; ++i) dis[i] = min(dis1[i], dis2[i]);

    sort(ALL(dis));

    int ans = 0;
    for(ll i: dis){
        if (k >= i) {
            k -= i;
            ans++;
        }
        else break;
    }
    return ans;
}

pair<ll, ll> get_mi_ma(ll x, ll y){
    return make_pair(min(x, y), max(x, y));
}


struct FenwickTree{
    int n;
    vector<ull> a;

    FenwickTree(int _n){
        n = _n;
        a.resize(n+1);
    }

    void update(int i, ull v){
        while(i <= n){
            a[i] += v;
            i += LASTBIT(i);
        }
    }

    ull get(int i){
        ull ans = 0;
        while(i > 0){
            ans += a[i];
            i -= LASTBIT(i);
        }
        return ans;
    }

    ull get(int l, int r){return get(r) - get(l-1);}

    int binary_lift(ull x){
        int p = MASK(logOf(n)), idx =0;
        while(p > 0){
            if (idx + p <= n && x >= a[idx + p]){
                idx += p;
                x -= a[idx];
            }
            p >>= 1;
        }
        return idx;
    }
};


int greedy2(vector<pair<ll, ll>> pdis, ll k){
    if (pdis.size() == 0) return 0;
    sort(ALL(pdis), [](pair<ll, ll> x, pair<ll, ll> y){return x.second < y.second;});
    int m = pdis.size();

    vector<pair<ll, int>> val;
    val.push_back({-1, -1});
    for(int i = 0; i < m; ++i){
        val.push_back({pdis[i].first, i * 2});
        if (pdis[i].second != INF){
            val.push_back({pdis[i].second - pdis[i].first, i * 2 + 1});
        }
    }
    sort(ALL(val));

    for(int i = 1; i < (int) val.size(); ++i){
        int idx = val[i].second / 2;
        if (val[i].second % 2 == 0){
            pdis[idx].first = i;
        }
        else{
            pdis[idx].second = i;
        }
    }

    int t = val.size() - 1;
    FenwickTree bit(t), sum(t);

    for(pair<ll, ll> i: pdis) {
        bit.update(i.first, 1); sum.update(i.first, val[i.first].first);
    }
    int ans = bit.get(sum.binary_lift(k));

    for(int i = 0; i < m; ++i){
        pair<ll, ll> cur = pdis[i];
        bit.update(cur.first, -1); sum.update(cur.first, -val[cur.first].first);
        k -= val[cur.first].first;
        if (k < 0) break;
        if (cur.second != INF){
            bit.update(cur.second, 1); sum.update(cur.second, val[cur.second].first);
        }

        maximize(ans, i + 1 + bit.get(sum.binary_lift(k)));
    }

    return ans;
}

int max_score(int _n, int x, int y, ll k, vector<int> U, vector<int> V, vector<int> W){
    n = _n;
    reset();

    for(int i = 0; i < n - 1; ++i) {
        int u = U[i], v = V[i], w = W[i];
        graph[u].push_back({v, w});
        graph[v].push_back({u, w});
    }

    dis[x] = 0;
    dfs(x, -1);

    vector<bool> on_chain(n);
    int _y = y;
    while(_y != x){
        on_chain[_y] = true;
        _y = parent[_y];
    }
    on_chain[x]= true;

    vector<ll> dis1(n);
    for(int i = 0; i < n; ++i) dis1[i] = dis[i];

    dis[y] = 0;
    dfs(y, -1);

    vector<ll> dis2(n);
    for(int i = 0; i < n; ++i) dis2[i] = dis[i];

    int ans1 = greedy1(dis1, dis2, k);
    
    vector<pair<ll, ll>> pdis;
    int ans2 = 0;
    for(int i = 0; i < n; ++i) {
        if (on_chain[i]){
            k -= min(dis1[i], dis2[i]);
            pdis.push_back({abs(dis1[i] - dis2[i]), INF});
            ans2++;
        }
        else{
            pdis.push_back(get_mi_ma(dis1[i], dis2[i]));
        }
    }

    if (k >= 0) ans2 += greedy2(pdis, k);
    else ans2 = -1; 

    return max(ans1, ans2);
}


// int main(void){
//     ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);

//     clock_t start = clock();

//     int t; cin >> t;
//     while(t--) {
//         int n, x, y; ll k; cin >> n >> x >> y >> k;
//         vector<int> u(n-1), v(n-1), w(n-1);
//         for(int i = 0; i < n-1; ++i) cin >>u[i] >> v[i] >> w[i];
//         // for(int i = 1; i < n; ++i) cout << rngesus(0, i-1) << " " << i << " " << rngesus(1, 10) << "\n";

//         cout << max_score(n, x, y, k, u, v, w) << "\n";
//     }
    

//     cerr << "Time elapsed: " << clock() - start << " ms\n";
//     return 0;
// }

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 9 / 9
• Subtask 6: 11 / 11
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 17 / 17