Pagini recente » Cod sursa (job #1105281) | Cod sursa (job #905024) | Cod sursa (job #546486) | Cod sursa (job #546480) | Cod sursa (job #534676)
Cod sursa(job #534676)
#include<iostream>
#include<fstream>
#include<vector>
#include<limits.h>
using namespace std;
struct nod{
int value;
vector<int> next;
vector<int> dist;};
nod*nnod(){
nod*dummy;
dummy=new nod;
dummy->value=INT_MAX;
return dummy;}
vector<nod*> graf;
class heap{
public:
int n;
vector<int> v;
heap(int lng);
void insert(int value);
int min();
int size();
private:
int parent(int pos);
int l_child(int pos);
int r_child(int pos);
void swap(int a,int b);
void relax();
bool isleaf(int pos);
bool exist(int pos);
};
heap::heap(int lng){
n=0;
v.resize(lng,0);}
void heap::insert(int value){
int i;
v[n]=value;
n++;
i=n;
while(exist(parent(i))&&graf[v[parent(i)]]->value>graf[v[i]]->value){
swap(v[parent(i)],v[i]);
i=parent(i);}}
int heap::min(){
if(n>0){
swap(v[0],v[n-1]);
n--;}
if(n!=0)relax();
return v[n];}
int heap::size(){
return n;}
int heap::parent(int pos){
return (int)((pos-1)/2);}
int heap::l_child(int pos){
return pos*2+1;}
int heap::r_child(int pos){
return pos*2+2;}
void heap::swap(int a,int b){
int x=a;
a=b;b=x;}
void heap::relax(){
int i,j;
i=0;
while(!isleaf(i)){
j=l_child(i);
if(exist(r_child(i))&&graf[v[r_child(i)]]->value<graf[v[j]]->value)j=r_child(i);
if(graf[v[i]]->value<graf[v[j]]->value)return;
swap(v[i],v[j]);
i=j;}}
bool heap::isleaf(int pos){
return (!exist(l_child(pos))&&!exist(r_child(pos)));}
bool heap::exist(int pos){
return pos<n;}
void dijkstra(heap*h){
int i=0;
graf[0]->value=0;
h->insert(0);
while(h->size()!=0){
i=h->min();
for(int j=0;j<graf[i]->next.size();j++){
if(graf[graf[i]->next[j]]->value>graf[i]->value+graf[i]->dist[j])graf[graf[i]->next[j]]->value=graf[i]->value+graf[i]->dist[j];
h->insert(graf[i]->next[j]);}}}
int main(){
int n,m,a,b,c;
heap*h;
ifstream f("dijkstra.in");
f>>n>>m;
h=new heap(n);
for(int i=0;i<n;i++)graf.push_back(nnod());
for(int i=0;i<m;i++){
f>>a>>b>>c;
graf[a-1]->next.push_back(b-1);
graf[a-1]->dist.push_back(c);}
f.close();
dijkstra(h);
ofstream g("dijkstra.out");
for(int i=1;i<n;i++)g<<graf[i]->value<<' ';
g.close();
return 0;}