Submission #1127631

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127631		_callmelucian	Rigged Roads (NOI19_riggedroads)	C++17	100 / 100	388 ms	42052 KiB

riggedroads

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tpl;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 3e5 + 5;

struct BIT {
    vector<int> tr;
    BIT (int sz) : tr(sz + 1) {}

    int p (int k) { return k & -k; }

    void update (int k, int val) {
        for (; k < tr.size(); k += p(k)) tr[k] += val;
    }

    int preSum (int k, int ans = 0) {
        for (; k; k -= p(k)) ans += tr[k];
        return ans;
    }

    int query (int l, int r) { return preSum(r) - preSum(l - 1); }

    int walk (int targ) {
        int ans = 0, lg = 31 - __builtin_clz(tr.size()), sum = 0;
        for (int mask = 1 << lg; mask; mask >>= 1) {
            if ((ans | mask) < tr.size() && sum + tr[ans | mask] < targ) ans |= mask, sum += tr[ans];
        }
        return ans;
    }

    int walkRange (int targ, int from) {
        int need = targ + preSum(from - 1);
        return walk(need);
    }
} tree(mn);

int num[mn], chain[mn], depth[mn], sz[mn];
int par[mn], idx[mn], place[mn], node[mn];
int checkPoint, timeDfs, n, m;

vector<pii> adj[mn];
bool inTree[mn];
pii edge[mn];

vector<int> clearRange (int l, int r) {
    vector<int> vec;
    while (int cur = tree.query(l, r)) {
        int pos = tree.walkRange(cur, l) + 1;
        vec.push_back(node[pos]);
        tree.update(pos, -1);
    }
    return vec;
}

int szDfs (int u, int p) {
    sz[u] = 1;
    for (pii item : adj[u]) {
        int v = item.first;
        if (v != p) sz[u] += szDfs(v, u);
    }
    return sz[u];
}

void dfs (int u, int p, int d, int upID, bool toP) {
    if (u == 1) szDfs(u, p);
    else idx[u] = upID;

    num[u] = ++timeDfs, depth[u] = d, node[timeDfs] = u;
    chain[u] = (toP ? chain[p] : u), par[u] = p;
    sort(all(adj[u]), [&] (pii a, pii b) {
            return sz[a.first] > sz[b.first];
         });
    bool heavy = 1;
    for (pii item : adj[u]) {
        int v, id; tie(v, id) = item;
        if (v != p) dfs(v, u, d + 1, id, heavy), heavy = 0;
    }
}

void append (vector<int> &source, const vector<int> &app) {
    source.insert(source.end(), all(app));
}

void process (int a, int b) {
    vector<int> vec;
    while (chain[a] != chain[b]) {
        int ap = par[chain[a]], bp = par[chain[b]];
        if (depth[ap] == depth[bp]) {
            append(vec, clearRange(num[chain[a]], num[a])), a = ap;
            append(vec, clearRange(num[chain[b]], num[b])), b = bp;
        }
        else if (depth[ap] > depth[bp])
            append(vec, clearRange(num[chain[a]], num[a])), a = ap;
        else if (depth[bp] > depth[ap])
            append(vec, clearRange(num[chain[b]], num[b])), b = bp;
    }
    if (depth[a] > depth[b]) swap(a, b);
    if (num[a] + 1 <= num[b]) append(vec, clearRange(num[a] + 1, num[b]));

    sort(all(vec), [&] (int a, int b) { return idx[a] < idx[b]; });
    for (int u : vec) place[idx[u]] = ++checkPoint;
}

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

    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int a, b; cin >> a >> b;
        edge[i] = {a, b};
    }
    for (int i = 1; i < n; i++) {
        int id, a, b; cin >> id;
        inTree[id] = 1, tie(a, b) = edge[id];
        adj[a].emplace_back(b, id);
        adj[b].emplace_back(a, id);
    }
    dfs(1, 0, 1, -1, 0);

    for (int i = 2; i <= n; i++) tree.update(num[i], 1);
    for (int i = 1; i <= m; i++) {
        int a, b; tie(a, b) = edge[i];
        if (depth[a] < depth[b]) swap(a, b);
        if (inTree[i]) {
            if (!place[i]) place[i] = ++checkPoint, tree.update(num[a], -1);
            cout << place[i] << " ";
        }
        else {
            process(a, b);
            cout << ++checkPoint << " ";
        }
    }

    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 9 / 9
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 12 / 12
• Subtask 7: 32 / 32