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Cod sursa(job #594886)
#include <cstdio>
#include <vector>
#include <bitset>
using namespace std;
#define MAX 50005
#define INF 0x3f3f3f3f
//<parsing>
FILE* fin=fopen("dijkstra.in","r");
const unsigned maxb=8192;
char buf[maxb];
unsigned ptr=maxb;
inline unsigned getInt(){
unsigned nr=0;
while(buf[ptr]<'0'||'9'<buf[ptr])
if(++ptr>=maxb)
fread(buf,maxb,1,fin),ptr=0;
while('0'<=buf[ptr]&&buf[ptr]<='9'){
nr=nr*10+buf[ptr]-'0';
if(++ptr>=maxb)
fread(buf,maxb,1,fin),ptr=0;
}
return nr;
}
//</parsing>
typedef vector<pair<int,int> >::iterator iter;
int n,m,heap[MAX],poz[MAX],d[MAX],l;
vector<pair<int,int> > g[MAX];
bitset<MAX> viz;
#define min(a,b) (((a)<(b))?(a):(b))
void swapH(int a,int b){
int aux=heap[a];
heap[a]=heap[b];
heap[b]=aux;
poz[heap[a]]=a;
poz[heap[b]]=b;
}
void upHeap(int k){
while( (k>>1) && d[heap[k>>1]]>d[heap[k]] ){
swapH(k,k>>1);
k>>=1;
}
}
void downHeap(int p){
int q=0;
while(q!=p){
q=p;
if((q<<1)<=l && d[heap[q<<1]] < d[heap[p]] ) p=q<<1;
if((q<<1)+1<=l && d[heap[(q<<1)+1]] < d[heap[p]] ) p=(q<<1)+1;
swapH(p,q);
}
}
void dijkstra(){
for(int i=1;i<=n;i++){
d[i]=INF;
heap[i]=poz[i]=i;
}
d[1]=0,l=n;
while(l){
int top=heap[1];
viz[heap[1]]=true;
swapH(1,l);
l--;
downHeap(1);
for(iter it=g[top].begin();it!=g[top].end();it++){
if(!viz[it->first]&&(d[it->first]>d[top]+it->second)){
d[it->first]=d[top]+it->second;
upHeap(poz[it->first]);
}
}
}
}
int main(){
FILE* fout=fopen("dijkstra.out","w");
n = getInt (), m = getInt ();
int x,y,c;
for(int i=0;i<=m;i++){
x = getInt (), y = getInt (), c = getInt ();
g[x].push_back(make_pair(y,c));
}
dijkstra();
for(int i=2;i<=n;i++){
fprintf(fout,"%d ",(d[i]==INF)?0:d[i]);
}
fclose(fin);
fclose(fout);
return 0;
}