Cod sursa(job #643307)

Utilizator mihaidutescuDutescu Mihai mihaidutescu Data 3 decembrie 2011 13:42:34
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.68 kb
#include <cstdio>

struct vecin
{
	int nod,cost;
	vecin* adr_urm;
};

vecin *vec[50001];

struct elc
{
	int nod;
	elc* adr_urm,*adr_prev;
};

elc *start,*end;

unsigned short int numapp[50001],eincoada[50001];

void vpush(int x,int y,int c)
{
	vecin* tmp=new vecin;
	tmp->nod=y;
	tmp->cost=c;
	tmp->adr_urm=vec[x];
	vec[x]=tmp;
}

void push(int n)
{
	if(!start)
	{
		start=new elc;
		end=start;
		start->nod=n;
		start->adr_urm=start->adr_prev=NULL;
	}
	else
	{
		elc* tmp=new elc;
		tmp->nod=n;
		tmp->adr_urm=start;
		start->adr_prev=tmp;
		start=tmp;
	}
}

void pop()
{
	if(end!=start)
	{
		elc *tmp=end->adr_prev;
		delete end;
		end=tmp;
	}
	else
	{
		delete end;
		end=start=NULL;
	}
}

int main()
{
	int cost[50001],n,m,x,y,c,nod;
	bool cicneg=false;
	start=end=NULL;
	for(int i=0;i<=50000;i++)
	{
		cost[i]=2100000000;
		eincoada[i]=numapp[i]=0;
		vec[i]=NULL;
	}
	FILE *f=fopen("bellmanford.in","r");
	fscanf(f,"%d %d\n",&n,&m);
	for(int i=0;i<=m;i++)
	{
		fscanf(f,"%d %d %d",&x,&y,&c);
		vpush(x,y,c);
	}
	fclose(f);
	cost[1]=0;
	push(1);
	while(end&&!cicneg)
	{
		nod=end->nod;
		pop();
		eincoada[nod]=0;
		for(vecin* curs=vec[nod];curs;curs=curs->adr_urm)
			if(cost[nod]+curs->cost<cost[curs->nod])
			{
				cost[curs->nod]=cost[nod]+curs->cost;
				if(!eincoada[curs->nod])
				{
					if(numapp[curs->nod]==n)
						cicneg=true;
					else
					{
						push(curs->nod);
						eincoada[curs->nod]=1;
						numapp[curs->nod]++;
					}
				}
			}
	}
	f=fopen("bellmanford.out","w");
	if(cicneg)
		fprintf(f,"Ciclu negativ!");
	else
		for(int i=2;i<=n;i++)
			fprintf(f,"%d ",cost[i]);
	return 0;
}