Nu aveti permisiuni pentru a descarca fisierul grader_test9.in
Cod sursa(job #1371409)
Utilizator | Data | 3 martie 2015 21:19:59 | |
---|---|---|---|
Problema | Algoritmul lui Dijkstra | Scor | 50 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 1.52 kb |
#include <cstdio>
#include <vector>
#include <queue>
#define NMAX 50001
#define INF 1<<30
using namespace std;
FILE* fin=fopen("dijkstra.in","r");
FILE* fout=fopen("dijkstra.out","w");
int n,m,dist[NMAX];
vector <pair <int,int> > G[NMAX];
struct comp
{
bool operator()(pair <int,int> a , pair <int,int> b){return a.second<b.second;}
};
priority_queue < pair<int,int>,vector<pair <int,int> >,comp> pq;
void citire();
void dijkstra();
int main()
{
citire();
dijkstra();
return 0;
}
void citire()
{
int i,a,b,c;
fscanf (fin,"%d %d",&n,&m);
for (i=1; i<=m; i++)
{
fscanf( fin,"%d %d %d",&a,&b,&c);
G[a].push_back(make_pair(b,c));
}
}
void dijkstra()
{
int i,nod,cost;
bool ok;
for (i=1; i<=n; i++) dist[i]=INF;
dist[1]=0;
pq.push(make_pair(1,0));
while (!pq.empty())
{
do
{
ok=1;
nod=pq.top().first; cost=pq.top().second;
pq.pop();
if (dist[nod]!=cost) ok=0;
}
while (ok==0);
for (i=0; i<G[nod].size(); i++)
{
if (dist[G[nod][i].first]> dist[nod] + G[nod][i].second)
{
dist[G[nod][i].first]=dist[nod] + G[nod][i].second;
pq.push( make_pair( G[nod][i].first,dist[G[nod][i].first]));
}
}
}
for (i=2; i<=n; i++)
{
if (dist[i]!=INF) fprintf(fout,"%d ",dist[i]);
else fprintf(fout,"0 ");
}
fprintf(fout,"\n");
}