Submission #1124066

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124066		ljtunas	Autići (COCI22_autici)	C++20	20 / 50	168 ms	33540 KiB

Main

// author : anhtun_hi , nqg
// 25-26.12.2024

#include <bits/stdc++.h>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v)    memset(h, v, sizeof h)
#define Forv(i, a)     for(auto& i : a)
#define For(i, a, b)   for(int i = a; i <= b; ++i)
#define Ford(i, a, b)  for(int i = a; i >= b; --i)
#define c_bit(i)     __builtin_popcountll(i)
#define Bit(mask, i)    ((mask >> i) & 1LL)
#define onbit(mask, i)  ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
#define Log2(x) (63 - __builtin_clzll(x))
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
using namespace std;

using ll = long long;
using ii = pair<ll, ll>;
using db = long double;
using ull = unsigned long long;

namespace std {
    template <typename T, int D>
    struct _vector : public vector <_vector <T, D - 1>> {
        static_assert(D >= 1, "Dimension must be positive!");
        template <typename... Args>
        _vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
    };
    template <typename T> struct _vector <T, 1> : public vector <T> {
        _vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
    };
    template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
    template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 1e6 + 5;
const  ll  mod = 1e9 + 7;
const  ll   oo = 1e18;

//#define int long long

int n, d[MAXN], pos[MAXN];
array<ll, 3> E[MAXN];

struct disjoint_set{
    int par[MAXN];
    void init() {
        For(i, 1, n) par[i] = -1;
    }
    int find(int u) {
        return (par[u] < 0) ? u : (par[u] = find(par[u]));
    }
    bool merge(int u, int v) {
        u = find(u), v = find(v);
        if (u == v) return false;
        if (par[u] > par[v]) swap(u, v);
        par[u] += par[v], par[v] = u;
        return true;
    }
} dsu;

void Solve() {
    cin >> n;
    For(i, 1, n) cin >> d[i];
    sort(d + 1, d + n + 1);
    priority_queue<ii, vector<ii>, greater<ii>> pq;
    For(i, 1, n){
        pos[i] = i + 1;
        if (pos[i] <= n) pq.push({d[i] + d[pos[i]], i});
    }
    int cntEdge = 0, cnttime = 0;
    while(pq.size() && cnttime <= 1e7){
        ++cnttime;
        auto [val, i] = pq.top(); pq.pop();
        E[++cntEdge] = {val, i, pos[i]};
        ++pos[i];
        if (pos[i] <= n) pq.push({d[i] + d[pos[i]], i});
    }
    sort(E + 1, E + cntEdge + 1);
    int cnt = 0; ll ans = 0;
    dsu.init();
    For(i, 1, cntEdge){
        if (cnt == n - 1) break;
        auto [w, u, v] = E[i];
//        cerr << u << ' ' << v << '\n';
        if (dsu.merge(u, v)){
            ++cnt;
            ans += w;
        }
    }
    cout << ans << '\n';
}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    if(fopen("a.inp", "r")) {
        freopen("a.inp", "r", stdin);
        freopen("a.out", "w", stdout);
    }

    int t = 1;
//    cin >> t;
    while(t --) Solve();
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:100:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |         freopen("a.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
Main.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen("a.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20