Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

func (pq *PQ) Push(x interface{}) {
	*pq = append(*pq, x.(Node))
}

func (pq *PQ) Pop() interface{} {
	old := *pq
	n := len(old)
	x := old[n-1]
	*pq = old[0 : n-1]
	return x
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, d[i])
	}
	wtr.Flush()
}

C++: #include <cstdio>
#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
using namespace std;
typedef pair<int ,int> P;
struct edge {int to,cost;};
const int INF=1000000000;
int N;
int d[10000];
vector<edge> G[10000];
void dijkstra(int s){
  for(int i=0;i<N;i++)d[i]=INF;
  d[s]=0;
  priority_queue<P,vector<P>,greater<P> > que;
  que.push(P(0,s));
  while(!que.empty()){
    P p=que.top();
    que.pop();
    int v=p.second;
    if(d[v]<p.first)continue;
    for(int i=0;i<G[v].size();i++){
      edge e=G[v][i];
      if(d[e.to]>d[v]+e.cost){
	d[e.to]=d[v]+e.cost;
	que.push(P(d[e.to],e.to));
      }
    }
  }
}

int main(){
  scanf("%d",&N);
  for(int i=0;i<N;i++){
    int u,k,c,v;
    scanf("%d %d",&u,&k);
    for(int j=0;j<k;j++){
      scanf("%d %d",&v,&c);
      edge e;e.to=v;e.cost=c;
      G[u].push_back(e);
    }
  }
  dijkstra(0);
  for(int i=0;i<N;i++)printf("%d %d\n",i,d[i]);
  return 0;
}

C++: #include <stdio.h>
#include <vector>
#include <algorithm>


using namespace std;

short heap_index[10000];

struct Info{
	Info(){
		to=0;
		weight = 0;
	}
	Info(short arg_to,int arg_weight){
		to = arg_to;
		weight = arg_weight;
	}
	short to;
	int weight;
};

class InfoPQ{
public:
	InfoPQ(){
		array = new Info[10000];
		n = 0;
	}
	void push(Info arg_info){
		array[n] = arg_info;
		int tmp = n;
		while(tmp != 0 && array[tmp].weight < array[(tmp-1)/2].weight){
			std::swap(array[tmp], array[(tmp-1)/2]);
			tmp = (tmp-1)/2;
		}
		n++;
	}

	bool isEmpty(){
		return n == 0;
	}

	void writeHeapIndex(){
		for(int i=0;i<n;i++){
			heap_index[array[i].to] = i;
		}
	}

	void update(short update_index,int new_weight){
		array[heap_index[update_index]].weight = new_weight;
		int tmp = heap_index[update_index];
		while(tmp != 0 && array[tmp].weight < array[(tmp-1)/2].weight){
			std::swap(heap_index[array[tmp].to],heap_index[array[(tmp-1)/2].to]);
			std::swap(array[tmp], array[(tmp-1)/2]);
			tmp = (tmp-1)/2;
		}
	}

	Info pop(){
		Info ret = array[0];
		n--;
		heap_index[array[n].to] = 0;
		std::swap(array[0],array[n]);
		int tmp = 0;
		while(2*tmp+1 <= n-1){
			if(2*tmp+2 <= n-1){
				if(array[2*tmp+2].weight < array[tmp].weight && array[2*tmp+2].weight <= array[2*tmp+1].weight){
					std::swap(heap_index[array[tmp].to],heap_index[array[2*tmp+2].to]);
					std::swap(array[2*tmp+2],array[tmp]);
					tmp = 2*tmp+2;
				}else if(array[2*tmp+1].weight < array[tmp].weight && array[2*tmp+1].weight <= array[2*tmp+2].weight){
					std::swap(heap_index[array[tmp].to],heap_index[array[2*tmp+1].to]);
					std::swap(array[2*tmp+1],array[tmp]);
					tmp = 2*tmp+1;
				}else{
					break;
				}
			}else{
				if(array[tmp].weight > array[2*tmp+1].weight){
					std::swap(heap_index[array[tmp].to],heap_index[array[2*tmp+1].to]);
					std::swap(array[tmp],array[2*tmp+1]);
					tmp = 2*tmp+1;
				}else{
					break;
				}
			}
		}
		return ret;
	}

private:
	Info* array;
	int n;
};



int main(){
	int n,count=0,tmp,left_node,right_node,dist;
	scanf("%d",&n);
	vector<Info> V[n];
	Info catcher;
	InfoPQ A;

	int P[n],zero_dist[n];

	for(int i=0;i<n;i++){
		P[i]=0;
		zero_dist[i] = 10000001;
	}
	zero_dist[0] = 0;
	P[0]=1;

	for(int i=0;i<n;i++){
		scanf("%d %d",&left_node,&tmp);
		if(left_node == 0){
			for(int k=0;k<tmp;k++){
				scanf("%d %d",&right_node,&dist);
				zero_dist[right_node] = dist;
			}
		}else{
			for(int k=0;k<tmp;k++){
				scanf("%d %d",&right_node,&dist);
				V[left_node].push_back(Info(right_node,dist));
			}
		}
	}

	for(short k=1;k<n;k++){
		A.push(Info(k,zero_dist[k]));
	}

	A.writeHeapIndex();

	while(count<n-1){

		catcher = A.pop();
		P[catcher.to]=1;
		count++;

		for(int k=0;k<V[catcher.to].size();k++){
			if(zero_dist[V[catcher.to][k].to] > catcher.weight+V[catcher.to][k].weight){
				zero_dist[V[catcher.to][k].to] = catcher.weight+V[catcher.to][k].weight;
				A.update(V[catcher.to][k].to,catcher.weight+V[catcher.to][k].weight);
			}
		}
	}

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

    return 0;
}