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 <cassert>
#include <climits>
#include <algorithm>
#include <iostream>
#include <vector>
#include <list>
#include <string>


class TVertex;
struct TPath
{
    int Cost;
    TVertex* Target;
    TPath(TVertex* ATarget, int ACost)
     : Target(ATarget), Cost(ACost) {}
};
bool Compare(const TPath& Left, const TPath& Right)
{
    if(Left.Cost  < 0) return false;
    if(Right.Cost < 0) return true;
    return Left.Cost < Right.Cost;
}
class TVertex
{
    int FIndex;
    std::vector<TPath> FList;
    int FDistance;

public:
    TVertex(int Index)
     : FIndex(Index), FDistance(INT_MAX)
    {}
    void AddPath(const TPath& Path)
    {
        FList.push_back(Path);
    }
    void SortPath()
    {
        std::sort(FList.begin(), FList.end(), Compare);
    }
    void PrintDistance(std::ostream& out)const
    {
        out << FIndex << " " << FDistance << std::endl;
    }
    void BreadthFirstSearch(int Distance)
    {
        if(FDistance <= Distance) return;
        FDistance = Distance;
        for(std::vector<TPath>::iterator It = FList.begin(); It != FList.end(); ++It){
            It->Target->BreadthFirstSearch(Distance + It->Cost);
        }
    }
};
class TGraph
{
    std::vector<TVertex*> FTable;
    void Init(int n)
    {
        assert(n > 0);
        FTable.resize(n);
        for(int i = 0; i < n; ++i){
            FTable[i] = new TVertex(i);
        }
    }
public:
    TGraph(int n)
    {
        Init(n);
    }
    
    void SetupVertex(std::istream& in)
    {
        int Index;
        in >> Index;
        assert(Index >= 0);
        assert(Index < FTable.size());
        int k;
        in >> k;
        for(int i = 0; i < k; ++i){
            int v, c;
            in >> v >> c;
            FTable[Index]->AddPath(TPath(FTable[v], c));
        }
        FTable[Index]->SortPath();
    }
    void BreadthFirstSearch()
    {
        FTable[0]->BreadthFirstSearch(0);
    }
    void PrintDistance(std::ostream& out)
    {
        for(int i = 0; i < FTable.size(); ++i){
            FTable[i]->PrintDistance(out);
        }
    }
};

int main()
{
    std::cin.tie(0);
    std::ios::sync_with_stdio(false);
    int n;
    std::cin >> n;
    TGraph Graph(n);
    for(int i = 0; i < n; ++i){
        Graph.SetupVertex(std::cin);
    }
    Graph.BreadthFirstSearch();
    Graph.PrintDistance(std::cout);
    return 0;
    
}

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

int n;
static const int nmax = 20005;
static const int INFTY = (1<<21);
static const int WHITE = 0; // Not visited
static const int GRAY = 1;  // Visited
static const int BLACK = 2; // In MST
using pair = std::pair<int, int>;
std::array<std::vector<pair>, nmax> adjlist;
std::array<int, nmax> d;
std::array<int, nmax> color;

void dijklstra(int s)
{
  color.fill(WHITE);
  d.fill(INFTY);


  auto priority = [](pair x, pair y){return x.second > y.second;};
  std::priority_queue<
    pair,
    std::vector<pair>,
    decltype(priority)
    > pq(priority);

  pq.push(std::make_pair(s, 0));
  color[s] = GRAY;
  d[s] = 0;

  while (!pq.empty())
    {
      auto u = pq.top();
      pq.pop();
      //std::cout << u.first << ' ' << u.second << std::endl;
      if (d[u.first] < u.second)
        continue;

      color[u.first] = BLACK;
      d[u.first] = u.second;

      for (int i=0; i<adjlist[u.first].size(); ++i)
        {
          auto v = adjlist[u.first][i];
          if ( (color[v.first] != BLACK) && ((d[u.first] + v.second) < d[v.first]))
            {
              d[v.first] = d[u.first] + v.second;
              color[v.first] = GRAY;
              pq.push(std::make_pair(v.first, d[v.first]));
            }
        }
    }


}

void print_distance(int v)
{
  dijklstra(v);

  for (int i=0; i<n; ++i)
    {
      std::cout << i << " " << d[i] << std::endl;
    }
}

int main ()
{
  std::cin >> n;

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

  print_distance(0);
}

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;
}