Submission #1087624

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087624		steveonalex	Construction of Highway (JOI18_construction)	C++17	100 / 100	405 ms	20692 KiB

construction

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
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(ll 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());
    }

struct FenwickTree{
    int n; 
    vector<int> a, b;

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

    void assign(int i, int v){
        int diff = v - b[i];
        update(i, diff);
    }

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

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

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

struct SegmentTree{ // assign;
    int query_cnt;
    int n;
    vector<pair<int, int>> a;

    SegmentTree(int _n){
        n = _n;
        a.resize(n * 2 + 2);
    }

    void update(int l, int r, int v){
        pair<int, int> cur = {++query_cnt, v};
        l += n; r += n + 1;
        while(l < r){
            if (l & 1) maximize(a[l++], cur);
            if (r & 1) maximize(a[--r], cur);
            l >>= 1; r >>= 1;
        }
    }

    int get(int i){
        i += n;
        pair<int, int> ans = {0, 0};
        while(i > 0){
            maximize(ans, a[i]);
            i >>= 1;
        }
        return ans.second;
    }

};

const int N = 1e5 + 69;

int n;
int a[N];
vector<int> graph[N];
int idx[N];
int sz[N], parent[N], h[N];

void find_sz(int u, int p){
    sz[u] =1;
    h[u] = h[p] + 1;
    parent[u] = p;
    for(int v: graph[u]) {
        find_sz(v, u);
        sz[u] += sz[v];
    }
}

int dfs_cnt = 0;
int in[N], head[N];
void decompose(int u, int p, bool flag){
    in[u] = ++dfs_cnt;
    if (flag) head[u] = u;
    else head[u] = head[p];

    pair<int, int> heavy = {-1, -1};
    for(int v: graph[u]) maximize(heavy, make_pair(sz[v], v));
    if (heavy.second == -1) return;
    decompose(heavy.second, u, 0);
    for(int v: graph[u]) if (v != heavy.second)
        decompose(v, u, 1);
}

vector<pair<int, int>> get_chain(int u){
    vector<pair<int,int>> ans;
    while(u != 0){
        int v = head[u];
        ans.push_back({in[v], in[u]});
        u = parent[v];
    }
    return ans;
}

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();

    cin >> n;
    for(int i = 1; i<=n; ++i) cin >> a[i];
    vector<int> X = {0};
    for(int i = 1; i<=n; ++i) X.push_back(a[i]);
    remove_dup(X);
    for(int i = 1; i<=n; ++i) 
        a[i] = lower_bound(ALL(X), a[i]) - X.begin();

    for(int i = 1; i<=n-1; ++i){
        int a, b; cin >> a >> b;
        idx[i] = b;
        graph[a].push_back(b);
    }

    find_sz(1, 0);
    decompose(1, 0, 1);

    FenwickTree bit(n);
    FenwickTree inversion_counter(n);
    SegmentTree st(n);
    for(int i = 1; i<=n; ++i) {
        st.update(in[i], in[i], a[i]);
        bit.update(i, 1);
    }
    for(int i = 1; i<n; ++i){
        int v = idx[i];
        vector<pair<int,int>> chain = get_chain(parent[v]);

        vector<pair<int,int>> chim;
        for(pair<int,int> j: chain){
            int u = j.second;
            while(u >= j.first){
                int v = bit.binary_search(bit.get(u));
                maximize(v, j.first);
                bit.assign(v, 0);
                chim.push_back({u - v + 1, st.get(u)});
                u = v - 1;
            }
            bit.assign(j.first, 1);
            bit.assign(j.second + 1, 1);
        }

        for(pair<int, int> j: chain) {
            st.update(j.first, j.second, a[v]);
        }
        bit.assign(in[v], 1); bit.assign(in[v], 1);

        // cout << "Add node: " << v << "\n";
        // for(int i = 1; i<=n; ++i) cout << st.get(i) << " "; cout << "\n";
        // for(pair<int, int> j: chain) cout << j.first << " " << j.second << "\n";

        ll ans = 0;
        for(pair<int, int> j: chim){
            ans += 1LL * j.first * inversion_counter.get(j.second-1);
            inversion_counter.update(j.second, j.first);
        }
        for(pair<int, int> j: chim) inversion_counter.update(j.second, -j.first);

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

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 84 / 84