Submission #888156

#	Time	Username	Problem	Language	Result	Execution time	Memory
888156		Shayan86	Construction of Highway (JOI18_construction)	C++14	16 / 100	2091 ms	28008 KiB

construction

#include <bits/stdc++.h>
using namespace std;
 
#pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// Ofast, O0, O1, O2, O3, unroll-loops, fast-math, trapv
 
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
 
#define Mp          make_pair
#define sep         ' '
#define endl        '\n'
#define F	        first
#define S	        second
#define pb          push_back
#define all(x)      (x).begin(),(x).end()
#define kill(res)	cout << res << '\n', exit(0);
#define set_dec(x)	cout << fixed << setprecision(x);
#define fast_io     ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io     freopen("input.txt", "r", stdin) ; freopen("output.txt", "w", stdout);
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
const ll L = 18;
const ll sq = 400;
const ll N = 1e5 + 50;
const ll Mod = 1e9 + 7;
 
ll n, c[N], par[N][L], h[N], mx[N];
 
vector<int> edge, adj[N];
 
void dfs(int v, int p = 0){
    par[v][0] = p;
    for(int i = 1; i < L; i++){
        if(!par[v][i-1]) break;
        par[v][i] = par[par[v][i-1]][i-1];
    }
    for(int u: adj[v]){
        h[u] = h[v] + 1; dfs(u, v);
    }
}
 
int getPar(int v, int k){
    for(int i = 0; i < L; i++){
        if(k >> i & 1) v = par[v][i];
    }
    return v;
}
 
int lca(int v, int u){
    if(h[v] < h[u]) swap(u, v);
    v = getPar(v, h[v] - h[u]);
    if(u == v) return v;
 
    for(int i = L-1; i >= 0; i--){
        if(par[v][i] != par[u][i]){
            v = par[v][i]; u = par[u][i];
        }
    }
    return par[v][0];
}
 
void prep(int v){
    for(int u: adj[v]){
        prep(u); mx[v] = max(mx[v], mx[u]);
    }
    if(mx[v]) c[v] = c[edge[mx[v]]];
}
 
vector<int> vec;
vector<pii> block;
 
int bit[N], m;
 
void upd(int x, int y){
    for(; x <= m; x += x & (-x)) bit[x] += y;
}
 
int get(int x){
    int out = 0;
    for(; x; x -= x & (-x)) out += bit[x];
    return out;
}
 
ll solve(){
    vec.clear();
    for(auto i: block) vec.pb(i.F);
 
    sort(all(vec)); vec.resize(unique(all(vec)) - vec.begin());
    m = vec.size();
 
    int sum = 0; ll res = 0;
    for(auto [x, y]: block){
        int id = lower_bound(all(vec), x) - vec.begin() + 1;
        res += 1ll * y * (sum - get(id)); upd(id, y); sum += y;
    }
 
    fill(bit, bit + m+1, 0);
    return res;
}
 
int main(){
    fast_io;
 
    cin >> n;
 
    for(int i = 1; i <= n; i++) cin >> c[i];
 
    int u, v; edge.pb(1);
    for(int i = 1; i < n; i++){
        cin >> u >> v;
        adj[u].pb(v); edge.pb(v);
    }
 
    dfs(1);
 
    for(int i = 1; i < n; i++){
        block.clear(); 
        int tah = -1; v = edge[i];
        for(int j = i-1; j % sq != 0; j--){
            u = lca(v, edge[j]);
            if(h[u] > tah){
                block.pb({c[edge[j]], h[u] - tah});
                tah = h[u];
                if(tah == h[v]-1) break;
            }
        }
        vec.clear();
        while(h[v] - 1 > tah){
            v = par[v][0]; vec.pb(c[v]);
        }
        reverse(all(vec));
 
        for(int j: vec) block.pb({j, 1});
 
        cout << solve() << endl;

        if(i % sq == 0){
            fill(mx, mx + N, 0);
            for(int j = i; j > i - sq; j--) mx[edge[j]] = j;
            prep(1);
        }
    }
 
}

Compilation message (stderr)

construction.cpp: In function 'll solve()':
construction.cpp:96:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   96 |     for(auto [x, y]: block){
      |              ^

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 0 / 84