Cod sursă (job #757134)

#include <bits/stdc++.h>
#define fastio ios_base::sync_with_stdio(0), cin.tie(0), fin.tie(0);
using namespace std;
ofstream fout("zapada.out");

class edge
{
public:
    int x, y, cost;

    edge(int x, int y, int cost)
    {
        this->x = x;
        this->y = y;
        this->cost = cost;
    }

    bool operator<(const edge& a) const
    {
        return this->cost < a.cost;
    }
};

class InParser
{
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch()
    {
        ++sp;
        if (sp == 4096)
        {
            sp = 0;
            fread(buff, 1, 4096, fin);
        }
        return buff[sp];
    }

public:
    InParser(const char *nume)
    {
        fin = fopen(nume, "r");
        buff = new char[4096]();
        sp = 4095;
    }

    InParser &operator>>(int &n)
    {
        char c;
        while (!isdigit(c = read_ch()) && c != '-')
            ;
        int sgn = 1;
        if (c == '-')
        {
            n = 0;
            sgn = -1;
        }
        else
        {
            n = c - '0';
        }
        while (isdigit(c = read_ch()))
        {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }

    InParser &operator>>(long long &n)
    {
        char c;
        n = 0;
        while (!isdigit(c = read_ch()) && c != '-')
            ;
        long long sgn = 1;
        if (c == '-')
        {
            n = 0;
            sgn = -1;
        }
        else
        {
            n = c - '0';
        }
        while (isdigit(c = read_ch()))
        {
            n = 10 * n + c - '0';
        }
        n *= sgn;
        return *this;
    }
};

vector<int> t, Rank;

int Find(int i)
{
    if (t[i] == i)
        return i;
    return t[i] = Find(t[i]);
}

void Union(int x, int y)
{
    int x_root = Find(x);
    int y_root = Find(y);

    if (Rank[x_root] < Rank[y_root])
        t[x_root] = y_root;
    else if (Rank[x_root] > Rank[y_root])
        t[y_root] = x_root;
    else
    {
        t[x_root] = y_root;
        Rank[y_root]++;
    }
}

int prim(vector<edge> &edges, int n)
{
    sort(edges.begin(), edges.end());

    t.resize(n + 1);
    Rank.resize(n + 1, 0);

    for (int i = 1; i <= n; ++i)
        t[i] = i;

    int costMin = 0;

    for (auto &e : edges)
    {
        int x = e.x;
        int y = e.y;
        int cost = e.cost;

        if (Find(x) != Find(y))
        {
            costMin += cost;
            Union(x, y);
        }
    }

    return costMin;
}

int main()
{
    InParser fin("zapada.in");
    int n, m, k;
    fin >> n >> m >> k;

    vector<edge> edges;

    for (int i = 0; i < m; ++i)
    {
        int x, y, cost;
        fin >> x >> y >> cost;
        edges.emplace_back(x, y, cost);
    }

    int c0 = prim(edges, n);
    fout << c0 << '\n';

    for (int i = 0; i < k; ++i)
    {
        int x, y, cost;
        fin >> x >> y >> cost;
        edges.emplace_back(x, y, cost);
        int ck = prim(edges, n);
        fout << ck << '\n';
    }
    return 0;
}