Submission #996790

#	Time	Username	Problem	Language	Result	Execution time	Memory
996790		LOLOLO	Rigged Roads (NOI19_riggedroads)	C++17	100 / 100	335 ms	68808 KiB

riggedroads

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (ll)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 3e5 + 10;
vector <pair <int, int>> ed[N];
int p[N][19], in[N], ou[N], timer = 0, id[N], cc = 1, a[N], b[N], used[N], w[N], f[N], rev[N];

void dfs(int u, int v) {
    p[u][0] = v;
    for (int j = 1; j < 19; j++) {
        p[u][j] = p[p[u][j - 1]][j - 1];
    }

    timer++;
    in[u] = timer; 
    for (auto x : ed[u]) {
        if (x.f == v)
            continue;

        id[x.f] = x.s;
        rev[x.s] = x.f;
        dfs(x.f, u);
    }

    ou[u] = timer;
}

bool is(int a, int b) {
    return in[a] <= in[b] && ou[a] >= ou[b]; 
}

int lca(int a, int b) {
    if (is(a, b))
        return a;

    if (is(b, a))
        return b;

    for (int j = 18; j >= 0; j--) {
        if (is(p[a][j], b) == 0)
            a = p[a][j];
    }

    return p[a][0];
}

void upd(int i, int x) {
    for (; i < N; i += i & (-i))
        f[i] += x;
}

int get(int i) {
    i = in[i];
    int s = 0;
    for (; i; i -= i & (-i))
        s += f[i];

    return s;
}

vector <int> lst;
void path(int a, int c) {
    while (1) {
        int val = get(a);
        for (int j = 18; j >= 0; j--) {
            if (get(p[a][j]) == val)
                a = p[a][j];
        }

        if (is(a, c))
            break;

        lst.pb(id[a]);
        upd(in[a], -1);
        upd(ou[a] + 1, 1);
        a = p[a][0];
    }
}

void road(int a, int b) {
    int c = lca(a, b);
    path(a, c);
    path(b, c);
}

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

    in[0] = 0;
    ou[0] = 1e9;
    int n, e;
    cin >> n >> e;

    for (int i = 1; i <= e; i++) {
        cin >> a[i] >> b[i];
    }

    for (int i = 1; i < n; i++) {
        int x;
        cin >> x;
        used[x] = 1;
        ed[a[x]].pb({b[x], x});
        ed[b[x]].pb({a[x], x});
    }

    dfs(1, 0);

    for (int i = 2; i <= n; i++) {
        upd(in[i], 1);
        upd(ou[i] + 1, -1);
    }

    for (int i = 1; i <= e; i++) {
        if (used[i] == 0) {
            road(a[i], b[i]);
            sort(all(lst));
            for (auto x : lst) {
                w[x] = cc++;
            }

            lst.clear();
        }

        if (w[i] == 0) {
            w[i] = cc++;
            if (used[i]) {
                upd(in[rev[i]], -1);
                upd(ou[rev[i]] + 1, 1);
            }
        }

        cout << w[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