Submission #1254935

#	Time	Username	Problem	Language	Result	Execution time	Memory
1254935		CrabCNH	Construction of Highway (JOI18_construction)	C++20	16 / 100	181 ms	61096 KiB

construction

#include <bits/stdc++.h>

#define task     "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())
#define all(v) (v).begin(), (v).end()

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using namespace std;

template <class T> void minimize (T &t, T f) {if (t > f) t = f;}
template <class T> void maximize (T &t, T f) {if (t < f) t = f;}

const int maxN = 1e6 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

// khong tu code thi khong kha len duoc dau

struct Fenwick {
    int bit[maxN];
    
    inline void upd (int id, int val) {
        for (; id < maxN; id += id & (-id)) {
            bit[id] += val;
        }
    }
    
    inline int get (int id) {
        int res = 0;
        for (; id; id -= id & (-id)) {
            res += bit[id];
        }
        return res;
    }
};

int n;
int c[maxN], res[maxN];
vector <int> adj[maxN];
int par[maxN];
int height[maxN];
int head[maxN], pos[maxN], sz[maxN];
int timer = 0;
vector <pii> q, st[maxN], cur;
pii a[maxN], b[maxN];
Fenwick T;

void dfs (int u, int p) {
    sz[u] = 1;
    for (auto v : adj[u]) {
        if (v == p) {
            continue;
        }
        height[v] = height[u] + 1;
        dfs (v, u);
        sz[u] += sz[v];
    }
}

void HLD (int u, int p, int h) {
    pos[u] = ++timer;
    head[u] = h;
    if (sz (adj[u]) == 1 && u != 1) {
        return;
    }
    int nxt = 0, curMax = 0;
    for (auto v : adj[u]) {
        if (v == p) {
            continue;
        }
        if (curMax < sz[v]) {
            curMax = sz[v];
            nxt = v;
        }
    }
    HLD (nxt, u, h);
    for (auto v : adj[u]) {
        if (v != nxt && v != p) {
            HLD (v, u, v);
        }
    }
}

bool cmp (pii A, pii B) {
    return A.se < B.se;
}

int calInv () {
    int n = sz (cur);
    if (n == 0) {
        return 0;
    }
    sort (all (cur), cmp);
    // cout << "bruh " << n << '\n';
    // cout << "all ";
    // for (auto it : cur) {
        // cout << it.fi << ' ' << it.se << ' ';
    // }
    // cout << '\n';
    int j = 1;
    b[1] = cur[0];
    for (int i = 1; i < n; i ++) {
        if (cur[i].se == cur[i - 1].se) {
            b[j].fi = cur[i].fi;
        }
        else {
            j ++;
            b[j] = cur[i];
        }
    }
    n = j;
    // for (int i = 1; i <= n; i ++) {
        // cout << "skibidi " << b[i].fi << ' ' << b[i].se << '\n';
    // }
    for (int i = 1; i <= n; i ++) {
        a[i].fi = b[i].fi;
        if (i == 1) {
            a[i].se = b[i].se + 1;
        }
        else {
            a[i].se = b[i].se - b[i - 1].se;
        }
        //if (n == 2) cout << a[i].fi << ' ' << a[i].se << '\n';
    }
    int res = 0;
    for (int i = 1; i <= n; i ++) {
        res += (T.get (maxN - 1) - T.get (a[i].fi)) * a[i].se;
        //cout << T.get (a[i].fi + 1) << ' ' << a[i].fi << ' ' << a[i].se << '\n';
        T.upd (a[i].fi, a[i].se);
    }
    for (int i = 1; i <= n; i ++) {
        T.upd (a[i].fi, -a[i].se);
    }
    return res;
}

void updPath (int curNode, int val) {
    vector <pii> tmp;
    while (!st[head[curNode]].empty () && st[head[curNode]].back ().se <= height[curNode]) {
        auto [v, h] = st[head[curNode]].back ();
        tmp.push_back ({v, h});
        st[head[curNode]].pop_back ();
    }
    if (!st[head[curNode]].empty ()) {
        auto [v, h] = st[head[curNode]].back ();
        // if (v == 2) {
            // cout << "wtf " << '\n';
        // }
        tmp.push_back ({st[head[curNode]].back ().fi, height[curNode]});
    }
    st[head[curNode]].push_back ({val, height[curNode]});
    while (!tmp.empty ()) {
        cur.push_back (tmp.back ());
        tmp.pop_back ();
    }
    if (par[head[curNode]] != 0) {
        updPath (par[head[curNode]], val);
    }
    return;
}

void solve () {
    cin >> n;
    vector <int> zip;
    for (int i = 1; i <= n; i ++) {
        cin >> c[i];
        zip.push_back (c[i]);
    }
    sort (all (zip));
    zip.erase (unique (all (zip)), zip.end ());
    for (int i = 1; i <= n; i ++) {
        c[i] = lower_bound (all (zip), c[i]) - zip.begin () + 1;
        //cout << c[i] << ' ';
    }
    //cout << '\n';
    for (int i = 1; i <= n - 1; i ++) {
        int u, v;
        cin >> u >> v;
        q.push_back ({u, v});
        par[v] = u;
        adj[u].push_back (v);
        adj[v].push_back (u);
    }
    dfs (1, 1);
    HLD (1, 1, 1);
    for (auto [u, v] : q) {
        cur.clear ();
        //cout << v << ' ' << c[v] << '\n';
        updPath (v, c[v]);
        cout << calInv () << '\n';
    }
    return;
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}
// thfv

Compilation message (stderr)

construction.cpp: In function 'int main()':
construction.cpp:207:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  207 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
construction.cpp:208:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  208 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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