제출 #892082

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
892082		kh0i	Sjekira (COCI20_sjekira)	C++17	110 / 110	37 ms	7236 KiB

sjekira

#include "bits/stdc++.h"
using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif

using ll = long long;
using pii = pair<int, int>;

#define F first
#define S second
#define sz(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll get_rand(ll l, ll r) {
    assert(l <= r);
    return uniform_int_distribution<ll> (l, r)(rng);
}

const int N = 1e5 + 3;

struct Edge{
    int u, v;
    ll w;
    bool operator < (const Edge &o) const {
        return w < o.w;
    }
};

struct DSU{
    vector<ll> p, sz, mx;
    int comp;

    void init(int n){
        p.resize(n + 2, 0);
        sz.resize(n + 2, 0);
        mx.resize(n + 2, 0);
        comp = n;
        for(int i = 1; i <= n; ++i)
            p[i] = i, sz[i] = 1, mx[i] = 0;
    }

    int find_set(int u){
        return u == p[u] ? u : p[u] = find_set(p[u]);
    }

    ll join_sets(int u, int v, ll x, ll y){
        u = find_set(u), v = find_set(v);
        mx[u] = max(mx[u], x);
        mx[v] = max(mx[v], y);
        if(u == v)
            return 0;
        --comp;
        if(sz[u] < sz[v])
            swap(u, v);
        ll res = mx[u] + mx[v];
        p[v] = u;
        sz[u] += sz[v];
        mx[u] = max(mx[u], mx[v]);
        return res;
    }
} dsu;

int n;
ll a[N];
vector<Edge> e;

void solve(){
    cin >> n;
    for(int i = 1; i <= n; ++i)
        cin >> a[i];
    for(int i = 1; i < n; ++i){
        int u, v;
        cin >> u >> v;
        ll w = max(a[u], a[v]);
        e.push_back({u, v, w});
    }
    sort(all(e));
    dsu.init(n);
    ll res = 0;
    for(auto [u, v, w] : e)
        res += dsu.join_sets(u, v, a[u], a[v]);
    cout << res;
}

int32_t main() {
    cin.tie(nullptr)->sync_with_stdio(0);
    #define task "paradigm"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int test = 1;
//    cin >> test;
    for(int i = 1; i <= test; ++i){
//        cout << "Case #" << i << ": ";
        solve();
    }
    #ifdef LOCAL
        cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
    #endif
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

sjekira.cpp: In function 'int32_t main()':
sjekira.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sjekira.cpp:95:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 30 / 30
• Subtask 4: 60 / 60