Cod sursa(job #2806845)

Utilizator Tache_RoxanaTache Roxana Tache_Roxana Data 23 noiembrie 2021 08:25:57
Problema Arbore partial de cost minim Scor 60
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 11.72 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <deque>
#include <stack>
#include <tuple>
#include <queue>
#include <list>
#include <algorithm>
using namespace std;

class Graph {
    struct nodeStruct {
        int node1, node2, cost;
        bool operator()(nodeStruct const& n1, nodeStruct const& n2) { return n1.cost > n2.cost; }
    };
    vector<list<nodeStruct>> adjacent;
    vector<list<nodeStruct>> transposed();
    void dfs(int &current, vector<bool>&visited, stack<int> &order);
    void bfs(int &start, vector<int> &costs, vector<bool> &visited, deque<int> &queue, int &diameter);
    void _biconnected(int &node, int parent, vector<bool> &visited, vector<int> &level, vector<int> &minLevel, stack<int> &s, vector<vector<int>> &components, vector<pair<int,int>> &criticalEdges);
    void _hardConnected(int &node, vector<bool> &visited, vector<vector<int>> &components, vector<list<nodeStruct>> &t);
    int findParent(int &node, vector<int> &parent);
    bool _hasPath(int &current, int &target, vector<bool> &visited);
public:
    Graph(vector<tuple<int, int, int>> &data, int nrNodes, bool oriented=true);
    Graph(int nrNodes) { adjacent.resize(nrNodes); }
    friend ostream& operator<< (ostream& os, Graph graph) {
        os << graph.adjacent.size() << " nodes\n";
        for(int i = 0; i < graph.adjacent.size(); i++) {
            os << "node " << i + 1 << ": ";
            for(nodeStruct j: graph.adjacent[i])
                os << "(" << j.node2 + 1 << ", " << j.cost << ") ";
            os << "\n";
        }
        return os;
    }
    int connected();
    pair<vector<int>, vector<bool>> costs(int start);
    stack<int> topologicalSort();
    pair<vector<vector<int>>, vector<pair<int,int>>> biconnected();
    vector<vector<int>> hardConnected();
    vector<int> dijkstra(int start);
    pair<vector<int>, bool> bellmanFord(int start);
    pair<vector<nodeStruct>, int> minimumTreeKruskall();
    bool havelHakimi(deque<int> degrees);
    int diameter();
    void insertEdge(int node1, int node2, int cost, bool oriented = true);
    bool hasPath(int current, int target);
};

int main() {
    ifstream in("apm.in");
    ofstream out("apm.out");
    vector<tuple<int, int, int>> data;
    int nrNodes, nrEdges;
    in >> nrNodes >> nrEdges;
    for(int i = 0; i < nrEdges; i++) {
        int aux1, aux2, cost;
        in >> aux1 >> aux2 >> cost;
        data.emplace_back(aux1 - 1, aux2 - 1, cost);
        data.emplace_back(aux2 - 1, aux1 - 1, cost);
    }
    Graph g(data, nrNodes);
    auto tree = g.minimumTreeKruskall();
    out << tree.second << "\n" << tree.first.size() << "\n";
    for(auto i: tree.first)
        out << i.node1 + 1 << " " << i.node2 + 1 << "\n";
    return 0;
}

Graph :: Graph(vector<tuple<int, int, int>> &data, int nrNodes, bool oriented) {
    adjacent.resize(nrNodes);
    for(auto[node1, node2, cost]: data) {
        adjacent[node1].push_back(nodeStruct({node1, node2, cost}));
        if(!oriented)
            adjacent[node2].push_back(nodeStruct({node2, node1, cost}));
    }
}
vector<list<Graph :: nodeStruct>> Graph :: transposed() {
    vector<list<nodeStruct>> ret(adjacent.size());
    for(int i = 0; i < adjacent.size(); i++)
        for(nodeStruct node: adjacent[i])
            ret[node.node2].push_back(nodeStruct({i, node.cost}));
    return ret;
}
void Graph :: dfs(int &current, vector<bool>&visited, stack<int> &order) {
    visited[current] = true;
    for(auto i: adjacent[current])
        if(!visited[i.node2])
            dfs(i.node2, visited, order);
    order.push(current);
}
void Graph :: bfs(int &start, vector<int> &costs, vector<bool> &visited, deque<int> &queue, int &diameter) {
    queue.push_back(start);
    visited[start] = true;
    costs[start] = 0;
    while(queue.empty() != 1) {
        const int current = queue.front();
        for(auto i: adjacent[current])
            if(!visited[i.node2]) {
                costs[i.node2] += (costs[current] + 1);
                diameter = costs[i.node2];
                visited[i.node2] = true;
                start = i.node2;
                queue.push_back(i.node2);
            }
        queue.pop_front();
    }
}
void Graph :: _biconnected(int &node, int parent, vector<bool> &visited, vector<int> &level, vector<int> &minLevel, stack<int> &s, vector<vector<int>> &components, vector<pair<int,int>> &criticalEdges) {
    visited[node] = true;
    minLevel[node] = level[node] = level[parent] + 1;
    s.push(node);
    for (auto x: adjacent[node])
        if (x.node2 != parent) {
            if (visited[x.node2])
                minLevel[node] = min(minLevel[node], level[x.node2]);
            else {
                _biconnected(x.node2, node, visited, level, minLevel, s, components, criticalEdges);
                minLevel[node] = min(minLevel[node], minLevel[x.node2]);
                if(level[node] < minLevel[x.node2])
                    criticalEdges.emplace_back(node, x.node2);
                if (minLevel[x.node2] >= level[node]) {
                    components.resize(components.size()+1);
                    while (s.top() != x.node2) {
                        components[components.size()-1].push_back(s.top());
                        s.pop();
                    }
                    components[components.size()-1].push_back(x.node2);
                    s.pop();
                    components[components.size()-1].push_back(node);
                }
            }
        }
}
void Graph :: _hardConnected(int &node, vector<bool> &visited, vector<vector<int>> &components, vector<list<nodeStruct>> &t) {
    visited[node] = false;
    components[components.size() - 1].push_back(node);
    for(auto j: t[node])
        if(visited[j.node2])
            _hardConnected(j.node2, visited, components, t);
}
int Graph :: findParent(int &node, vector<int> &parent) {
    if(node == parent[node])
        return node;
    return findParent(parent[node], parent);
}
bool Graph :: _hasPath(int &current, int &target, vector<bool> &visited) {
    if(visited[current])
        return false;
    visited[current] = true;
    if(current == target)
        return true;
    for(auto i: adjacent[current])
        if(_hasPath(i.node2, target, visited))
            return true;
    return false;
}
int Graph :: connected() {
    vector<bool> visited(adjacent.size());
    int nr = 0;
    for(int i = 0; i < adjacent.size(); i++)
        if(!visited[i]) {
            stack<int> _;
            nr++;
            dfs(i, visited, _);
        }
    return nr;
}
pair<vector<int>, vector<bool>> Graph :: costs(int start) {
    vector<int> costs(adjacent.size());
    vector<bool> visited(adjacent.size());
    deque<int> queue;
    int _;
    bfs(start, costs, visited, queue, _);
    return make_pair(costs, visited);
}
stack<int> Graph :: topologicalSort() {
    vector<bool> visited(adjacent.size());
    stack<int> order;
    for(int i = 0; i < adjacent.size(); i++)
        if(!visited[i])
            dfs(i, visited, order);
    return order;
}
pair<vector<vector<int>>, vector<pair<int,int>>> Graph :: biconnected(){
    stack<int> s;
    vector<int> level(adjacent.size()), minLevel(adjacent.size());
    vector<bool> visited(adjacent.size());
    vector<vector<int>> components;
    vector<pair<int,int>> criticalEdges;
    for (int i = 0; i < adjacent.size(); i++)
        if (visited[i] == 0)
            _biconnected(i, 0, visited, level, minLevel, s, components, criticalEdges);
    return make_pair(components, criticalEdges);
}
vector<vector<int>> Graph :: hardConnected() {
    stack<int> s;
    vector<bool> visited(adjacent.size());
    vector<vector<int>> components;
    vector<list<nodeStruct>> t = transposed();
    for(int i = 0; i < adjacent.size(); i++)
        if(!visited[i])
            dfs(i, visited, s);
    while(!s.empty()){
        if(visited[s.top()]){
            components.resize(components.size() + 1);
            _hardConnected(s.top(), visited, components, t);
        }
        s.pop();
    }
    return components;
}
vector<int> Graph :: dijkstra(int start) {
    vector<int> visited(adjacent.size()), distance(adjacent.size(), -1);
    priority_queue<nodeStruct, vector<nodeStruct>, nodeStruct> costs;
    vector<pair<int, int>> apm;
    costs.push({start, 0});
    distance[start] = 0;
    int cost = 0;
    while(costs.empty() != 1) {
        int node = costs.top().node2;
        costs.pop();
        if(!visited[node])
            for(auto i: adjacent[node]){
                if(!visited[i.node2])
                    if(distance[i.node2] == -1 || distance[i.node2] > i.cost + distance[node]){
                        distance[i.node2] = i.cost + distance[node];
                        costs.push({i.node2, distance[i.node2]});
                    }
            }
        visited[node] = 1;
    }
    return distance;
}
pair<vector<int>, bool> Graph :: bellmanFord(int start) {
    const int inf = 250001;
    vector<int> visited(adjacent.size()), distance(adjacent.size(), inf);
    priority_queue<nodeStruct, vector<nodeStruct>, nodeStruct> costs;
    costs.push({start, 0});
    distance[start] = 0;
    while(costs.empty() != 1) {
        int node = costs.top().node2;
        costs.pop();
        for(auto i: adjacent[node]){
            if(distance[i.node2] == inf || distance[i.node2] > i.cost + distance[node]){
                distance[i.node2] = i.cost + distance[node];
                costs.push({i.node2, distance[i.node2]});
                visited[node]++;
                if(visited[i.node2] >= adjacent.size())
                    return make_pair(distance, 1);
            }
        }
        visited[node]++;
    }
    return make_pair(distance, 0);
}
pair<vector<Graph :: nodeStruct>, int> Graph :: minimumTreeKruskall() {
    priority_queue<nodeStruct, vector<nodeStruct>, nodeStruct> sortedEdges;
    vector<int> parents(adjacent.size());
    vector<nodeStruct> minimumSearchTree;
    int cost = 0, nrEdges = 0;
    for(int i = 0; i < parents.size(); i++)
        parents[i] = i;
    for(int i = 0; i < adjacent.size(); i++)
        for(auto j: adjacent[i])
            sortedEdges.push(j);
    while(!sortedEdges.empty()) {
        nodeStruct node = sortedEdges.top();
        const int parent1 = findParent(node.node1, parents);
        const int parent2 = findParent(node.node2, parents);
        if(parent1 != parent2) {
            cost += node.cost;
            minimumSearchTree.push_back(node);
            parents[parent1] = parents[parent2];
            if(nrEdges == adjacent.size() - 1)
                break;
        }
        sortedEdges.pop();
    }
    return make_pair(minimumSearchTree, cost);
}
int Graph :: diameter() {
    vector<int> costs(adjacent.size());
    vector<bool> visited(adjacent.size());
    deque<int> queue;
    int current = 0, diameter;
    bfs(current, costs, visited, queue, diameter);
    fill(costs.begin(), costs.end(), 0);
    fill(visited.begin(), visited.end(), 0);
    bfs(current, costs, visited, queue, diameter);
    return diameter;
}
void Graph :: insertEdge(int node1, int node2, int cost, bool oriented) {
    adjacent[node1].emplace_back(nodeStruct{node1, node2, cost});
    if(!oriented)
        adjacent[node2].emplace_back(nodeStruct{node2, node1, cost});
}
bool Graph :: hasPath(int current, int target) {
    vector<bool> visited(adjacent.size());
    return _hasPath(current, target, visited);
}
bool Graph :: havelHakimi(deque<int> degrees) {
    int sum = 0;
    for(auto i: degrees) {
        sum += i;
        if(i >= degrees.size())
            return 0;
    }
    if(sum % 2)
        return 0;
    int nrNodes = degrees.size();
    while(1) {
        sort(degrees.begin(), degrees.end(),greater<>());
        if(degrees[0] == 0)
            return 1;
        const int currentDegree = degrees[0];
        degrees.pop_front();
        for(int i = 0; i < degrees.size(); i++) {
            degrees[i]--;
            if(degrees[i] < 0)
                return 0;
        }
    }
}