Submission #762594

#	Time	Username	Problem	Language	Result	Execution time	Memory
762594		GrindMachine	Rigged Roads (NOI19_riggedroads)	C++17	100 / 100	495 ms	81608 KiB

riggedroads

// Om Namah Shivaya
 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
 
#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)
 
template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}
 
template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}
 
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
 
/*
 
 
 
*/
 
const int MOD = 1e9 + 7;
const int N = 3e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
 
struct DSU {
    vector<int> par, rankk, siz;
    vector<pii> mn_depth;

    DSU() {

    }

    DSU(int n) {
        init(n);
    }

    void init(int n) {
        par = vector<int>(n + 1);
        rankk = vector<int>(n + 1);
        siz = vector<int>(n + 1);
        mn_depth = vector<pii>(n + 1);
        rep(i, n + 1) create(i);
    }

    void create(int u) {
        par[u] = u;
        rankk[u] = 0;
        siz[u] = 1;
    }

    int find(int u) {
        if (u == par[u]) return u;
        else return par[u] = find(par[u]);
    }

    bool same(int u, int v) {
        return find(u) == find(v);
    }

    void merge(int u, int v) {
        u = find(u), v = find(v);
        if (u == v) return;

        if (rankk[u] == rankk[v]) rankk[u]++;
        if (rankk[u] < rankk[v]) swap(u, v);

        par[v] = u;
        siz[u] += siz[v];
        amin(mn_depth[u], mn_depth[v]);
    }
};

vector<pii> adj[N];

struct lca_algo {
    // LCA template (for graphs with 1-based indexing)

    int LOG = 1;
    vector<int> depth;
    vector<vector<int>> up;
    vector<int> tin, tout;

    lca_algo() {

    }

    lca_algo(int n) {
        lca_init(n);
    }

    void lca_init(int n) {
        while ((1 << LOG) < n) LOG++;
        up = vector<vector<int>>(n + 1, vector<int>(LOG, 1));
        depth = vector<int>(n + 1);
        tin = vector<int>(n + 1);
        tout = vector<int>(n + 1);

        lca_dfs(1, -1);
    }

    int timer = 1;

    void lca_dfs(int node, int par) {
        tin[node] = timer++;

        for(auto [child,id] : adj[node]) {
            if (child == par) conts;

            up[child][0] = node;
            rep1(j, LOG - 1) {
                up[child][j] = up[up[child][j - 1]][j - 1];
            }

            depth[child] = depth[node] + 1;

            lca_dfs(child, node);
        }

        tout[node] = timer++;
    }

    int lift(int u, int k) {
        rep(j, LOG) {
            if (k & (1 << j)) {
                u = up[u][j];
            }
        }

        return u;
    }

    int query(int u, int v) {
        if (depth[u] < depth[v]) swap(u, v);
        int k = depth[u] - depth[v];
        u = lift(u, k);

        if (u == v) return u;

        rev(j, LOG - 1, 0) {
            if (up[u][j] != up[v][j]) {
                u = up[u][j];
                v = up[v][j];
            }
        }

        u = up[u][0];
        return u;
    }

    int get_dis(int u, int v) {
        int lca = query(u, v);
        return depth[u] + depth[v] - 2 * depth[lca];
    }

    bool ances(ll u, ll v){
        if(tin[u] <= tin[v] and tout[u] >= tout[v]){
            return true;
        }
        else{
            return false;
        }
    }
};

vector<pii> par(N);

void dfs(int u, int p){
    for(auto [v,id] : adj[u]){
        if(v == p) conts;
        par[v] = {u,id};
        dfs(v,u);
    }
}

void solve(int test_case)
{
    int n,m; cin >> n >> m;
    vector<pii> edges(m+5);
 
    rep1(i,m){
        int u,v; cin >> u >> v;
        edges[i] = {u,v};
    }
 
    vector<bool> in_mst(m+5);
    rep1(i,n-1){
        int id; cin >> id;
        in_mst[id] = 1;
        auto [u,v] = edges[id];
        adj[u].pb({v,id}), adj[v].pb({u,id});
    }

    lca_algo LCA(n);
    dfs(1,-1);

    DSU dsu(n+5);
    rep1(i,n) dsu.mn_depth[i] = {LCA.depth[i],i};

    vector<int> ans(m+5,-1);
    int ptr = 1;

    rep1(i,m){
        if(ans[i] != -1) conts;
        if(in_mst[i]){
            ans[i] = ptr++;
            dsu.merge(edges[i].ff, edges[i].ss);
            conts;
        }
        
        auto [u,v] = edges[i];
        int lca = LCA.query(u,v);

        vector<int> ids;

        while(true){
            auto [mn_depth, ances] = dsu.mn_depth[dsu.find(u)];
            u = ances;
            if(LCA.ances(u,lca)) break;

            auto [p,id] = par[u];
            ids.pb(id);
            dsu.merge(edges[id].ff, edges[id].ss);
        }

        while(true){
            auto [mn_depth, ances] = dsu.mn_depth[dsu.find(v)];
            v = ances;
            if(LCA.ances(v,lca)) break;

            auto [p,id] = par[v];
            ids.pb(id);
            dsu.merge(edges[id].ff, edges[id].ss);
        }

        sort(all(ids));

        trav(id,ids){
            assert(ans[id] == -1);
            ans[id] = ptr++;
        }

        ans[i] = ptr++;
    }
 
    rep1(i,m) cout << ans[i] << " ";
    cout << endl;
}
 
int main()
{
    fastio;
 
    int t = 1;
    // cin >> t;
 
    rep1(i, t) {
        solve(i);
    }
 
    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