Submission #391273

#	Time	Username	Problem	Language	Result	Execution time	Memory
391273		MrRobot_28	Sjekira (COCI20_sjekira)	C++17	110 / 110	161 ms	35524 KiB

sjekira

#include<bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define sz(a) (int)a.size()
#define ll long long
#define int long long
#define ld long double
const int N = 3e5 + 100;
int dsu[N];
int val[N];
int rang[N];
vector <pair <int, int> > vec[N];
int pred(int a)
{
    if(a == dsu[a]) return a;
    return dsu[a] = pred(dsu[a]);
}
void unite(int a, int b)
{
    a = pred(a);
    b = pred(b);
    if(rang[b] < rang[a])
    {
        swap(a, b);
    }
    dsu[b] = a;
    rang[a] += rang[b];
    val[a] = max(val[a], val[b]);
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n;
    cin >> n;
    vector <pair <int, int> > a(n);
    vector <set <pair <int, int> > > st(n);
    for(int i = 0; i < n; i++)
    {
        cin >> a[i].X;
        val[i] = a[i].X;
        a[i].Y = i;
        dsu[i] = i;
        rang[i] = 1;
    }
    sort(a.begin(), a.end());
    vector <vector <int> > g(n);
    for(int i = 0; i < n - 1; i++)
    {
        int a, b;
        cin >> a>> b;
        a--;
        b--;
        vec[a].push_back({a, b});
        vec[b].push_back({b, a});
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for(int i = 0; i < n; i++)
    {
        for(auto to : g[i])
        {
            if(val[to] > val[i] || val[to] == val[i] && to > i)
            {
                st[i].insert({val[to], to});
            }
        }
    }
    ll s = 0;
    for(int i = 0; i < n; i++)
    {
        int minto = -1;
        int v = a[i].Y;
        if(sz(st[v]) != 0)
        {
            pair <int, int> t = *st[v].begin();
            st[v].erase(t);
            s += t.X + val[v];
           // cout << t.X << " " << val[v] << "\n";
            if(sz(st[t.Y]) < sz(st[v]))
            {
                swap(st[t.Y], st[v]);
            }
            for(auto p : st[v])
            {
                st[t.Y].insert(p);
            }
        }
    }
    cout << s;
    return 0;
}

Compilation message (stderr)

sjekira.cpp: In function 'int main()':
sjekira.cpp:65:54: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   65 |             if(val[to] > val[i] || val[to] == val[i] && to > i)
      |                                    ~~~~~~~~~~~~~~~~~~^~~~~~~~~
sjekira.cpp:74:13: warning: unused variable 'minto' [-Wunused-variable]
   74 |         int minto = -1;
      |             ^~~~~

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