Submission #1114273

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114273		ljtunas	Sjekira (COCI20_sjekira)	C++14	110 / 110	58 ms	7628 KiB

sjekira

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define fi first
#define se second
#define Rep(i, n)  for(int i = 1; i <= n; ++i)
#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 Forv(v, h) for(auto &v : h)
#define Bit(x, i) ((x) >> (i) & 1ll)
#define onbit(x, i) ((x) | (1ll << i))
#define offbit(x, i) ((x) &~ (1ll << i))
#define cnt_bit(x) __builtin_popcountll(x)
#define Log2(x) (63 - __builtin_clzll(x))
#define all(h) h.begin(), h.end()
#define reset(h, v) (memset(h, v, sizeof(h)))
#define memoryof(v) (sizeof(v) / 1024 / 1024)

using ii  = pair<int, int>;
using ull = unsigned long long;
using db  = long double;
using vi  = vector<int>;
using vvi  = vector<vi>;
using vii  = vector<ii>;

const int dx[] = {0, 0, +1, -1};
const int dy[] = {-1, +1, 0, 0};
const int MAXN = 1e5  + 10;
const int  MOD = 1e9  + 7;
const int   oo = 1e18 + 1;
const int base = 311;

template <class X, class Y> bool maximize(X &a, const Y &b) {
    if(a < b) return a = b, true;
    return false;
}

template <class X, class Y> bool minimize(X &a, const Y &b) {
    if(a > b) return a = b, true;
    return false;
}

// (x, y) -> (u, v) = Ckn(u - x, x + y - u - v);
// Ckn(k, a) * Ckn(k, b) = C(a, a + b);  (k : 1 -> min(a, b))

void fixmod(int &val) {
    if (val < 0) val += MOD*MOD;
    val %= MOD;
}

int n, a[MAXN];
struct edge{
	int u, v;
};

int par[MAXN], ma[MAXN];
void init() {
	For (i, 1, n) par[i] = -1, ma[i] = a[i];
}

int Find(int u) {
	return (par[u] < 0) ? u : (par[u] = Find(par[u]));
}

void Merge(int u, int v) {
	u = Find(u), v = Find(v);
	if (u == v) return;
	if (par[u] > par[v]) swap(u, v);
	par[u] += par[v], maximize(ma[u], ma[v]);
	par[v] = u;
}

void Progess() {
	cin >> n;
	For(i, 1, n) cin >> a[i];
	vector <edge> vct;
	For(i, 1, n - 1) {
		int u, v;
		cin >> u >> v;
		vct.push_back({u, v});
	}
	sort (all(vct),[&](const edge &x, const edge &y){
		return max(a[x.u],a[x.v]) < max(a[y.u],a[y.v]);
	});
	int res = 0;
	init();
	Forv(tmp, vct) {
		int u = Find(tmp.u), v = Find(tmp.v);
		// cerr << u << ' ' << v << '\n';
		res += ma[u] + ma[v];
		Merge(u, v);
	}
	cout << res << '\n';
}

signed main(void) {
    ios_base::sync_with_stdio(false);cin.tie(nullptr);
    cout.tie(nullptr);

    #define task "main"
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }//_______________________________
    Progess();
    cerr << "\nTime elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s.\n";
    return (0 ^ 0);
}

Compilation message (stderr)

sjekira.cpp: In function 'int main()':
sjekira.cpp:104:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  104 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sjekira.cpp:105:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  105 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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