#include <bits/stdc++.h>
struct repRang{
int rep;
int rang;
};
// utila in implementarea structurii paduri de multimi disjuncte, pentru fiecare element tine minte reprezentantul si rangul
class Edge{
public:
int i, j, cost;
Edge(int _i, int _j, int _cost) : i(_i), j(_j), cost(_cost){}
friend bool operator<(const Edge& e1, const Edge& e2)
{
return e1.cost < e2.cost;
}
// util in ordonarea dupa cost
};
// o structura de tip muchie, utila in problema APM cand, aplicand algoritmul lui Kruskall avem nevoie sa sortam muchiile crescator dupa cost
const int nmax = 105;
using namespace std;
int extractMin(priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>>& pq){
int temp = pq.top().second;
pq.pop();
return temp;
}
// functie ce extrage nodul de cost minim dintre cele "nevizitate" la Dijkstra
class Graph{
int V, E;
vector<pair<int, int>> adj[nmax]; // lista de adiacenta ce contine perechi de tip {vecin, cost}
bool directed, weighted; // orientat / neorientat -- ponderat / neponderat
static int findRep(repRang*, int); // gaseste reprezentatul unui element in structura paduri de multimi disjuncte
static void reunion(repRang*, int, int); // reuneste doua multimi in structura paduri de multimi disjuncte
public:
Graph(bool, bool);
void DF(int, bool*); // pentru parcurgerea in adancime, parametru int care se refera la nodul curent si vector de bool care tine minte nodurile vizitate pana acum
void DFsol(ofstream&); // rezolva problema DFS - componente conexe de pe infoarena
void BFS(ofstream&, ifstream&); // rezolva problema BFS de pe infoarena, are parametri ifstream/ofstream ca sa stie de unde citeste / unde afiseaza
void DFbcc(int, bool*, int*, int*, ofstream&, vector<int>*, int&, stack<pair<int, int>>&); // DF - ul util in probleme componente biconexe
void Biconexe(ofstream&);
void DFts(int, bool*, stack<int>&); // DFS care creeaza stiva cu nodurile in ordinea inversa a timpului de parcurgere
void TopologicalSort(ofstream&);
void Kosaraju(ofstream&);
vector<pair<int, int>>* Transpose(); // construieste lista de adiacenta a grafului transpus
void DFtranspose(vector<pair<int, int>>*, vector<int>*, int, bool*, int); // DF pentru kosaraju, luand nodurile in ordinea de pe stiva, acest DF se face pe graful transpus
static void disjoint();
void build(ifstream&); // construim graful cu inputul aflat in parametrul de tip ifstream
void Kruskal(ofstream&);
void BellmanFord(ofstream&);
void Dijkstra(ofstream&);
void RoyFloyd(ifstream&, ofstream&); // deoarece inputul e prea diferit de majoritatea problemelor, fac citirea si afiseara direct in problema
static void HavelHakimi(); // algoritmul Havel-Hakimi, determina daca o secventa de numere poate reprezenta secventa gradelor unui graf
};
Graph::Graph(bool _directed, bool _weighted) : directed(_directed), weighted(_weighted){} // constructorul, parametri se initializeaza in functie de cerinta
void Graph::DF(int src, bool* vis){
vis[src] = true;
for(auto ngb: adj[src]){
if(vis[ngb.first] == false)
{
DF(ngb.first, vis);
}
}
}
void Graph::DFsol(ofstream& fout){
int total = 0;
bool vis[nmax] = {false};
for(int i = 1; i <= V; ++i)
if(vis[i] == false)
{
total++;
DF(i, vis);
}
fout << total;
}
// la problema BFS inputul era un pic diferit asa ca nu ma mai folosesc de metoda build, fac si citirea direct in metoda
void Graph::BFS(ofstream& fout, ifstream& fin){
int src;
fin >> V >> E;
fin >> src;
for(int i = 1; i <= E; ++i)
{
int k, j;
fin >> k >> j;
adj[k].push_back(make_pair(j, 0));
}
queue<int> q;
int dist[nmax];
for(int i = 1; i <= V; ++i)
dist[i] = - 1;
q.push(src);
dist[src] = 0;
while(!(q.empty())){
int top = q.front();
q.pop();
for(auto ngb : adj[top])
if(dist[ngb.first] == - 1){
dist[ngb.first] = dist[top] + 1;
q.push(ngb.first);
}
}
for(int i = 1; i <= V; ++i)
fout << dist[i] << ' ';
}
// parametrii sunt: nodul curent, vectorul de vizitat, vectorul cu nivelurile nodurilor, vectorul cu nivelurile minime ale nodurilor, fisierul unde afisez, vector<int> ssol[]
// care tine minte componentele, si stiva pe care o folosesc pt a determina componentele biconexe
void Graph::DFbcc(int nod, bool* vis, int* nivel, int* nivelMin, ofstream& fout, vector<int>* ssol, int& cnt, stack<pair<int, int>>& stt){
vis[nod] = true;
nivelMin[nod] = nivel[nod];
for(auto vecin: adj[nod]){
if(vis[vecin.first] == false)
{
nivel[vecin.first] = nivel[nod] + 1;
stt.push(make_pair(nod, vecin.first));
DFbcc(vecin.first, vis, nivel, nivelMin, fout, ssol, cnt, stt);
if(nivelMin[vecin.first] >= nivel[nod]){
ssol[cnt].push_back(nod);
while(!(stt.top().first == nod && stt.top().second == vecin.first))
{
ssol[cnt].push_back(stt.top().second);
stt.pop();
}
ssol[cnt].push_back(vecin.first);
stt.pop();
++cnt;
}
nivelMin[nod] = min(nivelMin[nod], nivelMin[vecin.first]);
}
else if (nivel[nod] - nivel[vecin.first] >= 2)
nivelMin[nod] = min(nivelMin[nod], nivel[vecin.first]);
}
}
void Graph::Biconexe(ofstream& fout){
bool vis[nmax] = {false};
int nivel[nmax];
nivel[1] = 0;
int nivelMin[nmax];
vector<int> ssol[nmax];
stack<pair<int, int>> stt;
int cnt = 0;
DFbcc(1, vis, nivel, nivelMin, fout, ssol, cnt, stt);
fout << cnt << '\n';
for(int i = 0; i < cnt; ++i){
for(auto el: ssol[i])
fout << el << ' ';
fout << '\n';
}
}
void Graph::DFts(int src, bool* vis, stack<int>& st){
for(auto ngb: adj[src])
if(vis[ngb.first] == false)
{
vis[ngb.first] = true;
DFts(ngb.first, vis, st);
}
st.push(src);
}
void Graph::TopologicalSort(ofstream& fout){
bool vis[nmax] = {false};
stack<int> st;
for(int i = 1; i <= V; ++i)
if(!(vis[i]))
{
vis[i] = true;
DFts(i, vis, st);
}
while(st.size())
{
fout << st.top() << ' ';
st.pop();
}
}
// df pe graful transpus, primeste ca parametru lista de adiacenta pt graful transpus, salveaza in sol componentele biconexe pe rand, node si visT sunt evidente, iar cnnt tine minte numarul
// componentei conexe
void Graph::DFtranspose(vector<pair<int, int>>* adjT, vector<int>* ssol, int node, bool* visT, int cnnt){
ssol[cnnt].push_back(node);
visT[node] = true;
for(auto vecin: adjT[node])
if(visT[vecin.first] == false)
{
DFtranspose(adjT, ssol, vecin.first, visT, cnnt);
}
}
void Graph::Kosaraju(ofstream& fout){
vector<pair<int, int>> adjT[nmax];
for(int i = 1; i <= E; ++i)
for(auto ngb : adj[i])
adjT[ngb.first].push_back(make_pair(i, 0));
bool visT[nmax] = {false};
bool vis[nmax] = {false};
stack<int> st;
vector<int> ssol[nmax];
for(int i = 1; i <= V; ++i)
if(!(vis[i]))
{
vis[i] = true;
DFts(i, vis, st);
}
int cnnt = 0;
while(st.size())
{
int k = 0;
while(st.size() && visT[st.top()] == true)
st.pop();
if(st.size())
k = 1;
if(st.size())
{
int crt = st.top();
DFtranspose(adjT, ssol, crt, visT, cnnt);
}
if(k == 1)
++cnnt;
if(st.size())
st.pop();
}
fout << cnnt << '\n';
for(int i = 0; i < cnnt; ++i)
{
for(auto el: ssol[i])
fout << el << ' ';
fout << '\n';
}
}
// Pentru problema disjoint, in array-ul info tinem minte pentru fiecare element reprezentantul si rangul
int Graph::findRep(repRang* info, int x){
if(x == info[x].rep)
return x;
return (info[x].rep = findRep(info, info[x].rep));
}
void Graph::reunion(repRang* info, int x, int y){
int repX = findRep(info, x);
int repY = findRep(info, y);
if(info[repX].rang > info[repY].rang)
info[repX].rep = repY;
else
if(info[repX].rang < info[repY].rang)
info[repY].rep = repX;
else
{
info[repX].rang++;
info[repY].rep = repX;
}
}
void Graph::disjoint(){
ifstream fin("disjoint.in");
ofstream fout("disjoint.out");
repRang* info = new repRang[nmax];
int N, M;
fin >> N >> M;
for(int i = 1; i <= N; ++i)
info[i].rep = i;
for(int i = 1; i <= M; ++i){
int cod, x, y;
fin >> cod >> x >> y;
if(cod == 2)
if(findRep(info, x) == findRep(info, y))
fout << "DA\n";
else
fout << "NU\n";
else
reunion(info, x, y);
}
delete[] info;
}
// construim graful, cu inputul venit din fisierul 'fin'
void Graph::build(ifstream& fin){
fin >> V >> E;
for(int i = 1; i <= E; ++i){
int src, dest, cost;
fin >> src >> dest;
adj[src].push_back(make_pair(dest, 0));
if(weighted){ // daca e ponderat, citim si costul
fin >> cost;
adj[src][adj[src].size() - 1].second = cost;
}
if(!directed) // daca e neorientat, pentru perechea citita x y il punem pe x in lista de adiacenta a lui y si pe y in lista de adiacenta a lui x
adj[dest].push_back(make_pair(src, 0));
}
}
void Graph::Kruskal(ofstream& fout){
vector<pair<int, int>> sol; // vectorul sol, unde tinem minte muchiile ce formeaza APM - ul
repRang reps[nmax];
vector<Edge> edges;
for(int i = 1; i <= V; ++i)
{
int src = i;
for(int j = 0; j < adj[i].size(); ++j){
int dest = adj[i][j].first;
int cost = adj[i][j].second;
if(src > dest){
Edge temp_edge = Edge(src, dest, cost);
edges.push_back(temp_edge);
}
}
}
int total = 0;
sort(edges.begin(), edges.end());
for(int i = 1; i <= V; ++i)
{
reps[i].rep = i;
reps[i].rang = 0;
}
int cnt = 0;
int i = 0;
for(;i < edges.size() && cnt <= E - 1; ++i){
Edge temp_edge = edges[i];
if(findRep(reps, edges[i].i) != findRep(reps, edges[i].j))
{
++cnt;
sol.push_back(make_pair(temp_edge.i, temp_edge.j));
reunion(reps, temp_edge.i, temp_edge.j);
total += temp_edge.cost;
}
}
fout << total << '\n';
fout << cnt << '\n';
for(auto edg: sol){
fout << edg.first << ' ' << edg.second << '\n';
}
}
void Graph::BellmanFord(ofstream& fout){
queue<int> q;
bool inQ[nmax] = {false};
int distMin[nmax];
int cnt[nmax] = {0};
distMin[1] = 0;
for(int i = 2; i <= V; ++i)
distMin[i] = INT_MAX / 2;
q.push(1);
inQ[1] = true;
while(!(q.empty())){
int i = q.front();
q.pop();
inQ[i] = false;
for(auto ngb: adj[i]){
int j = ngb.first;
int cost = ngb.second;
if(distMin[i] + cost < distMin[j]){
distMin[j] = distMin[i] + cost;
if(inQ[j] == false)
{ q.push(j);
inQ[j] = true;
++cnt[j];
if(cnt[j] > V)
{
fout << "Ciclu negativ!\n";
return;
}
}
}
}
}
for(int i = 2; i <= V; ++i)
fout << distMin[i] << ' ';
}
void Graph::Dijkstra(ofstream& fout){
// min heap-ul din Dijstrka, asa se implementeaza in C++, cu parametri astia mai 'ciudati'
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
int dMin[nmax];
dMin[1] = 0;
for(int i = 2; i <= V; ++i)
dMin[i] = INT_MAX / 2;
pq.push(make_pair(0, 1));
bool relaxedB4[nmax] = {false};
while(!(pq.empty())){
int crt = extractMin(pq);
if(relaxedB4[crt] == true)
continue;
relaxedB4[crt] = true;
for(auto ngb: adj[crt]){
int vv = ngb.first;
int ccost = ngb.second;
if(ccost + dMin[crt] < dMin[vv])
{
dMin[vv] = ccost + dMin[crt];
pq.push(make_pair(dMin[vv], vv));
}
}
}
for(int i = 2; i <= V; ++i)
if(dMin[i] != INT_MAX / 2)
fout << dMin[i] << ' ';
else fout << 0 << ' ';
}
void Graph :: HavelHakimi(){
vector<int> d;
cout << "Introduceti numarul de elemente ale array-ului: ";
int n; cin >> n;
cout << "Introduceti elementele array-ului: ";
int sum = 0;
for(int i = 0; i < n; ++i){
int temp; cin >> temp;
d.push_back(temp);
sum += temp;
if(temp > n - 1)
{
cout << "Nu se poate construi un graf!\n";
return;
}
}
if(sum % 2)
{
cout << "Nu se poate construi un graf!\n";
return;
}
while(d.size()){
sort(d.begin(), d.end(), greater<int>());
int biggest = d[0];
d.erase(d.begin());
for(int i = 0; i < biggest; ++i)
{
--d[i];
if(d[i] < 0){
cout << "Nu se poate construi un graf!\n";
return;
}
}
}
cout << "Se poate construi un graf\n";;
return;
}
void Graph::RoyFloyd(ifstream& in, ofstream& out){
int N;
in >> N;
int costMatrix[nmax][nmax]; // matricea costurilor
for(int i = 0; i < N; ++i)
for(int j = 0; j < N; ++j)
in >> costMatrix[i][j];
for(int k = 0; k < N; ++k)
// pana la pasul asta, am calculat distanta minima la i la j folosindu-ma de nodurile 0..k - 1 (DACA EXISTA!)
for(int i = 0; i < N; ++i)
for(int j = 0; j < N; ++j)
if(costMatrix[i][j] > costMatrix[i][k] + costMatrix[k][j] && (costMatrix[i][k] * costMatrix[k][j] != 0))
costMatrix[i][j] = costMatrix[i][k] + costMatrix[k][j];
for(int i = 0; i < N; ++i)
{
for(int j = 0; j < N; ++j)
out << costMatrix[i][j] << ' ';
out << '\n';
}
}
int main()
{
ifstream fin("royfloyd.in");
ofstream fout("royfloyd.out");
Graph g(true, true);
g.RoyFloyd(fin, fout);
return 0;
}