План электрификации

#pragma once
#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <vector>
#include <stdio.h>
#include <cmath>
#include <math.h>
#include <queue>
#include <stack>
#include <climits>
#include <deque>
#include <ctime>
#include <iomanip>
#include <bitset>
#include <unordered_map>
#include <unordered_set>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;

#define mh() make_heap()
#define poph() pop_heap()
#define pushh() push_heap()
#define sor(n) n.begin(), n.end()
#define rsor(n) n.rbegin(), n.rend()
#define mp make_pair
#define files freopen("input.txt", "rt", stdin); freopen("output.txt", "wt", stdout)
#define p(T) pair<T,T>
#define toch(x) cout.precision(x), cout.setf(ios::fixed)
#define znac(l) abs(l)/l
#define IOS ios::sync_with_stdio(false)
#define IOSB cin.tie(0), cout.tie(0);
const ll ok = ll(1e9 + 7);


void decs(ll ans, vector<pair<ll, p(ll)>>graf)
{

}
int dsu_get(int v, vector<ll> &pt) {
    return (v == pt[v]) ? v : (pt[v] = dsu_get(pt[v],pt));
}

void dsu_unite(int a, int b, vector<ll> &pt) {
    a = dsu_get(a,pt);
    b = dsu_get(b,pt);
    if (rand() & 1)
        swap(a, b);
    if (a != b)
        pt[a] = b;
}

int main()
{
    IOSB;
    IOS;
#ifdef TheCompiler
    files;
#endif
    ll n, k;
    cin >> n >> k;
    vector<ll> pt(n+1);
    for (int i = 1; i <= n; i++)
    {
        pt[i] = i;
    }
    vector<ll>el;
    ll p;
    cin >> p;
    el.push_back(p);
    ll r = p;
    for (int i = 2; i <= k; i++)
    {
        cin >> p;
        el.push_back(p);
        dsu_unite(p, r, pt);
    }
    vector<pair<ll,p(ll)>>graf;

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
        {
            ll p;
            cin >> p;
            if (i != j)
            {
                graf.push_back( { p,{ i,j } });
            }
        }
    sort(sor(graf));
    ll ans = 0;
    for (int i = 0; i < graf.size(); i++)
    {
        if (dsu_get(graf[i].second.first, pt) != dsu_get(graf[i].second.second, pt))
        {
            ans += graf[i].first;
            dsu_unite(graf[i].second.first, graf[i].second.second, pt);
        }
    }
    cout << ans;
    return 0;
}