Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int,int> > adj[MAX];

void dijkstra(){
  int i, j;
  priority_queue<pair<int,int> > P;
  int color[MAX];
  int d[MAX];
  for( i = 0 ; i < n ; i++ ){
    d[i] = INFTY;
    color[i] = WHITE;
  }

  d[0] = 0;
  P.push(make_pair(0,0));
  color[0] = GRAY;

  while( !P.empty() ){
    pair<int,int> f = P.top();
    P.pop();
    int u = f.second;
    color[u] = BLACK;
    if( d[u] < f.first*(-1) ) continue;

    for( j = 0 ; j < adj[u].size() ; j++ ){
      int v = adj[u][j].first;
      if( color[v] == BLACK ) continue;
      if( d[v] > d[u] + adj[u][j].second ){
	d[v] = d[u] + adj[u][j].second;
	P.push(make_pair(d[v]*(-1),v));
	color[v] = GRAY;
      }
    }
  }

  for( i = 0 ; i < n ; i++ ){
    cout << i << " " << ( d[i] == INFTY ? -1 : d[i] ) << endl;
  }
}

int main(){
  int i, j, k, u, v, c;

  cin >> n;

  for( i = 0 ; i < n ; i++ ){
    cin >> u >> k;
    for( j = 0 ; j < k ; j++ ){
      cin >> v >> c;
      adj[u].push_back(make_pair(v,c));
    }
  }

  dijkstra();

  return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

typedef pair<int,int> PII;
#define INF 1001001001
#define rep(i,n) for(int i=0; i<n; ++i)
#define mp make_pair

struct edge{
    int to;
    int cost;
    edge(int to,int cost):to(to),cost(cost){}
};

int V;
vector<edge> G[10000];
int d[10000];

void dijkstra(int s){
    priority_queue<PII, vector<PII>, greater<PII>> Q;
    fill(d,d+V,INF);
    d[s]=0;
    Q.push(mp(0,s));

    while(!Q.empty()){
        PII p=Q.top();Q.pop();
        int v=p.second;
        if(d[v]<p.first) continue;
        rep(i,G[v].size()){
            edge e=G[v][i];
            if(d[e.to]>d[v]+e.cost){
                d[e.to]=d[v]+e.cost;
                Q.push(mp(d[e.to],e.to));
            }
        }
    }
}
int n;
int main(){
    cin>>V;
    rep(i,V){
        rep(j,V){
            int u,k;
            cin>>u>>k;
            rep(t,k){
                int v, c;
                cin>>v>>c;
                G[u].push_back(edge(v,c));
            }
        }
    }
    dijkstra(0);
    rep(i,V){
        cout<<i<<" "<<d[i]<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <queue>
#include <algorithm>
using namespace std;

static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int,int> > adj[MAX];

void dijkstra(){
	priority_queue<pair<int, int> > PQ;
	int color[MAX];
	int d[MAX];
	for(int i=0;i<n;i++){
		d[i]=INFTY;
		color[i]=WHITE;
	}
	
	d[0]=0;
	PQ.push(make_pair(0,0));
	color[0]=GRAY;
	
	while(!PQ.empty()){
		pair<int, int> f = PQ.top();PQ.pop();
		int u=f.second;
		
		color[u]=BLACK;
		
		if(d[u]<f.first*(-1)) continue;
		
		for(int j=0;j<adj[u].size();j++){
			int v=adj[u][j].first;
			if(color[v]==BLACK) continue;
			
			if(d[v]>d[u]+adj[u][j].second){
				d[v]=d[u]+adj[u][j].second;
				PQ.push(make_pair(d[v]*(-1),v));
				color[v]=GRAY;
			}
		}
		
	}
	for(int i=0;i<n;i++){
		cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
	}
}



int main() {
	
	ios::sync_with_stdio(false); cin.tie(0); 
	
	int k,u,v,c;
	
	cin>>n;
	
	for(int i=0;i<n;i++){
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>v>>c;
			adj[u].push_back(make_pair(v,c));
		}
	}
	
	dijkstra();
	
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> node;
typedef vector<node> Adj_list;
typedef vector<Adj_list> Adj_lists;

class less_cost{
public:
  bool operator()(const pair<int, int> lhs, const pair<int, int> rhs) const{
    return lhs.second < rhs.second;
  }
};

int main(){

  int n;
  scanf("%d", &n);

  Adj_lists adj_lists(n);

  // read weigts
  for(int i=0; i<n; i++){
    int u, k;
    scanf("%d %d", &u, &k);
    for(int j=0; j<k; j++){
      int v,c;
      scanf("%d %d", &v, &c);
      adj_lists.at(u).push_back(node(v, c));
    }
  }

  // initialize cost
  vector<int> d(n, INT_MAX);
  d.at(0) = 0;
  priority_queue<node, vector<node>, less_cost> pq;
  pq.push(node(0, d.at(0)));

  //dijkstra's algorithm
  while(!pq.empty()){
    // extract node u in V-S that has minimum cost
    const node u = pq.top();
    pq.pop();

    // if u's cost is larger than d[u],
    // than ignore this one
    if(u.second < d.at(u.first)) continue;

    // update node in V-S and adjacent to u
    for(const node& v : adj_lists.at(u.first)){
      if(d.at(u.first) + v.second < d.at(v.first)){
        d.at(v.first) = d.at(u.first) + v.second;
        pq.push(make_pair(v.first, d.at(v.first)));
      }
    }
  }

  // output
  for(int i=0; i<n; i++){
    printf("%d %d\n", i, d[i]);
  }

  return 0;
}