Submission #919681

#	Time	Username	Problem	Language	Result	Execution time	Memory
919681		Nelt	ICC (CEOI16_icc)	C++17	0 / 100	3 ms	604 KiB

icc

#include "icc.h"
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma,popcnt")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

/* DEFINES */
#define S second
#define F first
#define ll long long
#define ull unsigned long long
#define ld long double
#define npos ULLONG_MAX
#define INF LLONG_MAX
#define vv(a) vector<a>
#define ss(a) set<a>
#define pp(a, b) pair<a, b>
#define mm(a, b) map<a, b>
#define qq(a) queue<a>
#define pq(a) priority_queue<a>
#define ump(a, b) unordered_map<a, b>
#define ANDROID                   \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define allc(a) begin(a), end(a)
#define all(a) a, a + sizeof(a) / sizeof(a[0])
#define elif else if
#define endl "\n"
#define pb push_back
#define ins insert
#define logi __lg
#define sqrt sqrtl
#define mpr make_pair
using namespace std;
using namespace __cxx11;
using namespace __gnu_pbds;
typedef char chr;
typedef basic_string<chr> str;
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
struct Dsu
{
    ll n, ans;
    vv(ll) dsu;
    vv(vv(ll)) s;
    Dsu(ll sz = 1)
    {
        n = sz;
        ans = n;
        dsu.resize(n + 1, 0);
        s.resize(n + 1);
        init();
    }
    void init()
    {
        for (ll i = 1; i <= n; i++)
            dsu[i] = -1, s[i] = {i};
    }
    bool Union(ll x, ll y)
    {
        x = repr(x), y = repr(y);
        if (x == y)
            return false;
        if (dsu[x] < dsu[y])
            swap(x, y);
        ans--;
        for (ll i : s[x])
            s[y].pb(i);
        s[x].clear();
        dsu[y] += dsu[x];
        dsu[x] = y;
        return true;
    }
    ll repr(ll x)
    {
        if (dsu[x] < 0)
            return x;
        return dsu[x] = repr(dsu[x]);
    }
    ll query()
    {
        return ans;
    }
    ll size(ll x)
    {
        return -dsu[repr(x)];
    }
};

void run(int n)
{
    Dsu dsu(n);
        ll p[n];
        iota(all(p), 1);
    for (ll cnt = 1; cnt < n; cnt++)
    {
        vv(int) v[2];
        shuffle(all(p), rng);
        for (ll bit = 0; bit <= logi(n); bit++)
        {
            v[0].clear(), v[1].clear();
            for (ll i : p)
                if (dsu.repr(i) == i)
                    for (ll j : dsu.s[i])
                        v[j >> bit & 1].pb(j);
            if (query(v[0].size(), v[1].size(), data(v[0]), data(v[1])))
                break;
        }
        ll l = 1, r = v[1].size(), a, b;
        while (l <= r)
        {
            ll mid = (l + r) >> 1;
            if (query(v[0].size(), mid, data(v[0]), data(v[1])))
                a = v[1][mid - 1], r = mid - 1;
            else    l = mid + 1;
        }
        l = 1, r = v[0].size();
        while (l <= r)
        {
            ll mid = (l + r) >> 1;
            if (query(mid, v[1].size(), data(v[0]), data(v[1])))
                b = v[0][mid - 1], r = mid - 1;
            else
                l = mid + 1;
        }
        dsu.Union(a, b);
        setRoad(a, b);
    }
}

Compilation message (stderr)

icc.cpp: In function 'void run(int)':
icc.cpp:80:18: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
   80 |         if (dsu[x] < 0)
      |                  ^
icc.cpp:113:39: note: 'b' was declared here
  113 |         ll l = 1, r = v[1].size(), a, b;
      |                                       ^
icc.cpp:80:18: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
   80 |         if (dsu[x] < 0)
      |                  ^
icc.cpp:113:36: note: 'a' was declared here
  113 |         ll l = 1, r = v[1].size(), a, b;
      |                                    ^

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 21
• Subtask 5: 0 / 29
• Subtask 6: 0 / 10