Submission #749180

#	Time	Username	Problem	Language	Result	Execution time	Memory
749180		stevancv	Construction of Highway (JOI18_construction)	C++14	0 / 100	2 ms	2644 KiB

construction

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 1e5 + 2;
const int inf = 1e9;
int a[N], b[N], c[N], inv[N], n;
vector<int> g[N];
int par[N][17], in[N], out[N], dep[N], tsz;
int st[4 * N];
void Add(int node, int l, int r, int p, int o) {
    if (l == r) {
        st[node] = o;
        return;
    }
    int mid = l + r >> 1;
    if (p <= mid) Add(2 * node, l, mid, p, o);
    else Add(2 * node + 1, mid + 1, r, p, o);
    st[node] = max(st[2 * node], st[2 * node + 1]);
}
int Get(int node, int l, int r, int ql, int qr) {
    if (r < ql || qr < l) return 0;
    if (ql <= l && r <= qr) return st[node];
    int mid = l + r >> 1;
    return max(Get(2 * node, l, mid, ql, qr), Get(2 * node + 1, mid + 1, r, ql, qr));
}
void Dfs(int s, int e) {
    in[s] = ++tsz;
    par[s][0] = e;
    for (int i = 1; i < 17; i++) par[s][i] = par[par[s][i - 1]][i - 1];
    Add(1, 1, n, in[s], inv[s]);
    for (int u : g[s]) {
        dep[u] = dep[s] + 1;
        Dfs(u, s);
    }
    out[s] = tsz;
}
bool Ancestor(int u, int v) {
    return in[u] <= in[v] && out[v] <= out[u];
}
int Lca(int u, int v) {
    if (Ancestor(u, v)) return u;
    if (Ancestor(v, u)) return v;
    for (int i = 16; i >= 0; i--) {
        if (par[u][i] && !Ancestor(par[u][i], v)) u = par[u][i];
    }
    return par[u][0];
}
ll sol;
struct Fenwick {
    ll bit[N];
    void Add(int x, int y) {
        for (; x < N; x += x & (-x)) bit[x] += y;
    }
    ll Get(int x) {
        ll ans = 0;
        for (; x > 0; x -= x & (-x)) ans += bit[x];
        return ans;
    }
}f;
void Resi(int s, int x) {
    int o = Get(1, 1, n, in[s], out[s]);
    int y = b[o];
    int lca = Lca(x, y);
    sol += f.Get(N - 1) - f.Get(c[y]);
    if (lca == x) return;
    f.Add(c[y], dep[lca] - dep[s] + 1);
    int l = 0, r = g[lca].size() - 1, gde = -1;
    while (l <= r) {
        int mid = l + r >> 1;
        if (in[g[lca][mid]] <= in[x]) {
            l = mid + 1;
            gde = mid;
        }
        else r = mid - 1;
    }
    Resi(g[lca][gde], x);
    f.Add(c[y], dep[s] - dep[lca] - 1);
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    vector<int> all;
    for (int i = 1; i <= n; i++) {
        cin >> c[i];
        all.push_back(c[i]);
    }
    sort(all.begin(), all.end());
    for (int i = 1; i <= n; i++) {
        c[i] = (int)(lower_bound(all.begin(), all.end(), c[i]) - all.begin()) + 1;
    }
    for (int i = 1; i < n; i++) {
        cin >> a[i] >> b[i];
        inv[b[i]] = i;
        g[a[i]].push_back(b[i]);
    }
    Dfs(1, 0);
    vector<int> ans;
    for (int i = n - 1; i >= 1; i--) {
        Add(1, 1, n, in[b[i]], 0);
        sol = 0;
        if (a[i] == 1) {
            ans.push_back(0);
            continue;
        }
        Resi(1, a[i]);
        ans.push_back(sol);
    }
    for (int i = n - 2; i >= 0; i--) cout << ans[i] << en;
    return 0;
}

Compilation message (stderr)

construction.cpp: In function 'void Add(int, int, int, int, int)':
construction.cpp:20:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   20 |     int mid = l + r >> 1;
      |               ~~^~~
construction.cpp: In function 'int Get(int, int, int, int, int)':
construction.cpp:28:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   28 |     int mid = l + r >> 1;
      |               ~~^~~
construction.cpp: In function 'void Resi(int, int)':
construction.cpp:74:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   74 |         int mid = l + r >> 1;
      |                   ~~^~~

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