Submission #521832

#	Time	Username	Problem	Language	Result	Execution time	Memory
521832		XEMPLI5	Bridges (APIO19_bridges)	C++17	100 / 100	2068 ms	158872 KiB

bridges

#include <bits/stdc++.h>
using namespace std;
 
#define gc getchar_unlocked
#define fo(i, n) for (int i = 0; i < n; i++)
#define rfo(i, n) for (int i = n - 1; i >= 0; i--)
#define REP(i, a, b) for (int i = a; i < b; i++)
#define RREP(i, a, b) for (int i = a; i >= b; i--)
#define ll long long
#define si(x) scanf("%d", &x)
#define sl(x) scanf("%lld", &x)
#define ss(s) scanf("%s", s)
#define pi(x) printf("%d\n", x)
#define pl(x) printf("%lld\n", x)
#define ps(s) printf("%s\n", s)
#define deb(x) cout << #x << "=" << x << endl
#define deb2(x, y) cout << #x << "=" << x << "," << #y << "=" << y << endl
#define deb3(x, y, z) cout << #x << "=" << x << "," << #y << "=" << y << "," << #z << "=" << z << endl
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define clr(x) memset(x, 0, sizeof(x))
#define sortall(x) sort(all(x))
#define tr(it, a) for (auto it = a.begin(); it != a.end(); it++)
#define PI 3.1415926535897932384626
 
typedef pair<int, int> pii;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpii;
typedef vector<pl> vpl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
 
int mpow(int base, int exp);
void dfs(int u, int par);
 
const int mod = 1'000'000'007;
const int N = 3e5, M = N;
 
vi g[N];
int a[N], ans[N];
vi par, sz;
int n = 0;
 
stack<int> stck;
void reset()
{
    fo(i, n)
    {
        par[i] = i;
        sz[i] = 1;
    }
}
 
int find(int a)
{
    while (a != par[a])
    {
        a = par[a];
    }
    return a;
}
 
void onion(int a, int b)
{
    a = find(a);
    b = find(b);
    if (a == b)
        return;
    if (sz[a] > sz[b])
        swap(a, b);
    stck.push(a);
    sz[b] += sz[a];
    par[a] = par[b];
}
 
void rollback(int siz)
{
    while (stck.size() > siz)
    {
        int k = stck.top();
        stck.pop();
        sz[par[k]] -= sz[k];
        par[k] = k;
    }
}
 
void solve()
{
    int m, q;
    cin >> n >> m;
    vi u(m), v(m), d(m);
    fo(i, m)
    {
        cin >> u[i] >> v[i] >> d[i];
        u[i]--;
        v[i]--;
    }
    cin >> q;
    vi b(q), r(q), s(q), w(q), ty(q);
    fo(i, q)
    {
        int t;
        cin >> t;
        if (t == 1)
        {
            cin >> b[i] >> r[i];
            b[i]--;
            ty[i] = 1;
        }
        else
        {
            cin >> s[i] >> w[i];
            s[i]--;
            ty[i] = 2;
        }
    }
    par.resize(n);
    sz.resize(n);
    vvi tojoin(q);
    vi ans(q);
    int bs = 1000;
    vi changed(m);
    for (int j = 0; j < q; j += bs)
    {
        reset();
        vi ask, update, nochange;
        fo(i, m) changed[i] = false;
        for (int i = j; i < min(j + bs, q); i++)
        {
            if (ty[i] == 1)
            {
                changed[b[i]] = true;
                update.pb(i);
            }
            else
            {
                ask.pb(i);
            }
        }
        fo(k, m) if (!changed[k]) nochange.pb(k);
        for (int i = j; i < min(j + bs, q); i++)
        {
            if (ty[i] == 1)
            {
                d[b[i]] = r[i];
            }
            else
            {
                tojoin[i].clear();
                for (auto e : update)
                    if (d[b[e]] >= w[i])
                        tojoin[i].pb(b[e]);
            }
        }
        sort(all(ask), [&](int a, int b)
             { return w[a] > w[b]; });
        sort(all(nochange), [&](int a, int b)
             { return d[a] > d[b]; });
        int ptr = 0;
        for (auto e : ask)
        {
            while (ptr < nochange.size() && d[nochange[ptr]] >= w[e])
            {
                onion(u[nochange[ptr]], v[nochange[ptr]]);
                ptr++;
            }
            int prv = stck.size();
            for (auto f : tojoin[e])
                onion(u[f], v[f]);
            ans[e] = sz[find(s[e])];
            rollback(prv);
        }
    }
    fo(i, q) if (ty[i] == 2) cout << ans[i] << '\n';
    return;
}
 
int main()
{
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    srand(chrono::high_resolution_clock::now().time_since_epoch().count());
 
    int t = 1;
    int cs = 0;
    while (t - cs)
    {
        solve();
        cs++;
    }
 
    return 0;
}
 
int mpow(int base, int exp)
{
    base %= mod;
    int result = 1;
    while (exp > 0)
    {
        if (exp & 1)
            result = ((ll)result * base) % mod;
        base = ((ll)base * base) % mod;
        exp >>= 1;
    }
    return result;
}
 
void ipgraph(int n, int m)
{
    int u, v;
    while (m--)
    {
        cin >> u >> v;
        u--, v--;
        g[u].pb(v);
        g[v].pb(u);
    }
}
 
void dfs(int u, int par)
{
    for (int v : g[u])
    {
        if (v == par)
            continue;
        dfs(v, u);
    }
}

Compilation message (stderr)

bridges.cpp: In function 'void rollback(int)':
bridges.cpp:83:24: warning: comparison of integer expressions of different signedness: 'std::stack<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   83 |     while (stck.size() > siz)
      |            ~~~~~~~~~~~~^~~~~
bridges.cpp: In function 'void solve()':
bridges.cpp:167:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  167 |             while (ptr < nochange.size() && d[nochange[ptr]] >= w[e])
      |                    ~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27