Cod sursă (job #757087)

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

class Edge {
public:
    int x, y, cost;
    Edge()
    {
        x=0;
        y=0;
        cost=0;
    }
    Edge(int x, int y, int cost)
        {
            this->x=x;
            this->y=y;
            this->cost=cost;
        }

    bool operator<(const Edge& a) const {
        return cost < a.cost;
    }
};

vector<int> parent, Rank;

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

void Union(int x, int y) {
    int xRoot = Find(x);
    int yRoot = Find(y);

    if (Rank[xRoot] < Rank[yRoot])
        parent[xRoot] = yRoot;
    else if (Rank[xRoot] > Rank[yRoot])
        parent[yRoot] = xRoot;
    else {
        parent[xRoot] = yRoot;
        Rank[yRoot]++;
    }
}

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;
    }

    InParser& operator>>(Edge &e) {
        *this >> e.x >> e.y >> e.cost;
        return *this;
    }

    ~InParser() {
        fclose(fin);
        delete[] buff;
    }
};

class OutParser {
private:
    ofstream fout;

public:
    OutParser(const string& filename) {
        fout.open(filename);
    }

    void writeInt(int x) {
        fout << x << '\n';
    }

    ~OutParser() {
        fout.close();
    }
};

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

    parent.resize(n + 1);
    Rank.assign(n + 1, 0);

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

    int minCost = 0;

    for (const Edge& e : edges) {
        int x = e.x;
        int y = e.y;

        if (Find(x) != Find(y)) {
            minCost += e.cost;
            Union(x, y);
        }
    }

    return minCost;
}

int main() {
    InParser in("zapada.in");
    OutParser out("zapada.out");

    int n, m, k;
    in >> n >> m >> k;

    vector<Edge> edges;

    for (int i = 0; i < m; ++i) {
        Edge e;
        in >> e;
        edges.push_back(e);
    }

    parent.resize(n + 1);
    Rank.assign(n + 1, 0);

    int c0 = kruskal(edges, n);
    out.writeInt(c0);

    for (int i = 0; i < k; ++i) {
        Edge e;
        in >> e;
        edges.push_back(e);
        int ck = kruskal(edges, n);
        out.writeInt(ck);
    }

    return 0;
}