Cod sursa(job #2219438)

Utilizator akaprosAna Kapros akapros Data 8 iulie 2018 22:27:14
Problema Floyd-Warshall/Roy-Floyd Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 2.52 kb
#include <bits/stdc++.h>
#define maxN 100
#define inf 1000000000
using namespace std;

FILE *fin = freopen("royfloyd.in", "r", stdin);
FILE *fout = freopen("royfloyd.out", "w", stdout);

typedef pair<int, int> iPair;

class Graph
{
    int V;
    list< pair<int, int> > *adj;
public:
    Graph(int V);
    void addEdge(int u, int v, int w);
    void BellmanFord(int s);
    void AddH();
    void Dijkstra(int s);

};

int h[maxN + 2], d[maxN + 2][maxN + 2];

Graph::Graph(int V)
{
    this->V = V;
    adj = new list<iPair> [V + 1];
}
void Graph::addEdge(int u, int v, int w)
{
    adj[u].push_back(make_pair(v, w));
}


void Graph::BellmanFord(int s)
{
    for (int u = 1; u <= V; ++ u)
        h[u] = inf;
    for (int j = 1; j < V; ++ j)
    {
        for (int u = 0; u <= V; ++ u)
            for (auto i = adj[u].begin(); i != adj[u].end(); ++ i)
            {
                int v = (*i).first;
                int w = (*i).second;
                if (h[v] > h[u] + w)
                    h[v] = h[u] + w;
            }
    }
}
void Graph::AddH()
{
    for (int u = 1; u <= V; ++ u)
        for (auto i = adj[u].begin(); i != adj[u].end(); ++ i)
            (*i).second += h[u] - h[(*i).first];
}
void Graph::Dijkstra(int s)
{
    priority_queue< iPair, vector <iPair>, greater<iPair> > pq;

    for (int u = 1; u <= V; ++ u)
        d[s][u] = inf;
    d[s][s] = 0;
    pq.push(make_pair(0, s));

    while (!pq.empty())
    {
        int u = pq.top().second;
        pq.pop();

        for (auto i = adj[u].begin(); i != adj[u].end(); ++ i)
        {
            int v = (*i).first;
            int weight = (*i).second;

            if (d[s][v] > d[s][u] + weight)
            {
                d[s][v] = d[s][u] + weight;
                pq.push(make_pair(h[v], v));
            }
        }
    }
}
int main()
{
    int n;
    scanf("%d", &n);
    Graph g(n);

    for (int u = 1; u <= n; ++ u)
    {
        g.addEdge(0, u, 0);
        for (int v = 1; v <= n; ++ v)
        {
            int w;
            scanf("%d", &w);
            d[u][v] = inf;
            if (w)
                g.addEdge(u, v, w);
        }
    }

    g.BellmanFord(0);
    g.AddH();

    for (int u = 1; u <= n; ++ u)
        g.Dijkstra(u);

    for (int u = 1; u <= n; ++ u, printf("\n"))
        for (int v = 1; v <= n; ++ v)
            if (d[u][v] == inf)
                printf("0 ");
            else
                printf("%d ", d[u][v] + h[v] - h[u]);

    return 0;
}