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 <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
constexpr int di[] = {0, 1, 0, -1}, dj[] = {1, 0, -1, 0};
#define rep(i, n) for (int i = 0; i < n; i++)
#define repr(i, n) for (int i = n; i >= 0; i--)
#define sort(v) sort((v).begin(), (v).end())
#define sortr(v) sort((v).rbegin(), (v).rend())
#define all(v) (v).begin(), (v).end()
#define max 10000005
#define nil -1
constexpr int inf = 100000000;

struct edge{
    int to,cost;
};

vector<vector<edge>> g;
vector<int> d;
int n;

void dic(int s){
    priority_queue<P,vector<P>,greater<P>> que;
    d.resize(max);
   fill(d.begin(),d.end(),inf);
   d[s]=0;
   que.push(P(0,s));
   while(!que.empty()){
       P p=que.top();que.pop();
       int v=p.second;
       if(p.first>d[v]){
           continue;
       }
       for(int i=0;i<g[v].size();i++){ 
           edge e=g[v][i];
           if(d[v]+e.cost<d[e.to]){
               d[e.to]=d[v]+e.cost;
               que.push(P(d[e.to],e.to));
           }
       }
   }
}

int main() {
  int  u,k,v,c;
  cin>>n;
    g.resize(n);
    d.resize(n);
  rep(i,n){
      cin>>u>>k;
      for(int j=0;j<k;j++){
          cin>>v>>c;
          g[u].push_back({v,c});
        }
    }
    dic(0);
    rep(i,n){
        cout<<i<<" "<<d[i]<<endl;
    }
  return 0;
}

C++: #include <bits/stdc++.h>
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define all(c) begin(c), end(c)
#define dump(x) cerr << __LINE__ << ":\t" #x " = " << (x) << endl

using Weight = ll;
using Capacity = int;
struct Edge {
    int src, dst;
    Weight weight;
    Edge() : src(0), dst(0), weight(0) {}
    Edge(int s, int d, Weight w) : src(s), dst(d), weight(w) {}
};
using Edges = std::vector<Edge>;
using Graph = std::vector<Edges>;
using Array = std::vector<Weight>;
using Matrix = std::vector<Array>;

void add_edge(Graph &g, int a, int b, Weight w = 1) {
    g[a].emplace_back(a, b, w);
    g[b].emplace_back(b, a, w);
}
void add_arc(Graph &g, int a, int b, Weight w = 1) {
    g[a].emplace_back(a, b, w);
}

Weight bidirectional_dijkstra(const Graph &g, int s, int t){
    if(s == t) return 0;
    constexpr Weight INF = std::numeric_limits<Weight>::max() / 2;
    int n = g.size();
    std::vector<Weight> dist[2];
    dist[0] = dist[1] = std::vector<Weight>(n, INF);
    dist[0][s] = dist[1][t] = 0;
    using state = std::pair<Weight, int>;
    std::priority_queue<state, std::vector<state>, std::greater<state>> q[2];
    q[0].emplace(0, s);
    q[1].emplace(0, t);
    Weight mu = INF;
    while (q[0].size() && q[1].size()) {
        if (q[0].top().first + q[1].top().first >= mu) break;
        int k = q[0].top().first <= q[1].top().first ? 0 : 1;
        Weight d;
        int v;
        std::tie(d, v) = q[k].top();
        q[k].pop();
        if (d < dist[k][v]) continue;
        for (auto &e: g[v]) {
            int w = e.dst;
            if (dist[k][w] > dist[k][v] + e.weight) {
                dist[k][w] = dist[k][v] + e.weight;
                q[k].emplace(dist[k][w], w);
                mu = std::min(mu, dist[k][v] + e.weight + dist[1 - k][w]);
            }
        }
    }
    return mu;
}

using namespace std;
int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    int n;
    cin >> n;
    Graph g(n);
    rep(i, n){
        int u, deg;
        cin >> u >> deg;
        rep(j, deg){
            int v, c;
            cin >> v >> c;
            add_arc(g, u, v, c);
        }
    }
    rep(i, n){
        cout << i << ' ' << bidirectional_dijkstra(g, 0, i) << '\n';
    }
}

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(){
  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(){
  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;
}