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<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define loop(i,a,b) for(i=a;i<b;i++)
#define rloop(i,a,b) for(i=a;i>=b;i--)
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
const int inf=1000000001;
const ll INF=1e16;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int N=10000;

int n;
vector< vector< pair<int,int> > > adj(N,vector< pair<int,int> >());
vi d(N,inf);

void dijkstra();

int main(){
	int k,u,v,c,i,j;
	cin>>n;
	loop(i,0,n){
		cin>>u>>k;
		loop(j,0,k){
			cin>>v>>c;
			adj[u].push_back(make_pair(c,v));
		}
	}
	dijkstra();
	loop(i,0,n){
		cout<<i<<" "<<((d[i]==inf)? -1:d[i])<<endl;
	}
}

void dijkstra(){
	priority_queue< pair<int,int>, vector< pair<int,int> >, greater< pair<int,int> > > pq;
	int i;
	vi color(n,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){
			continue;
		}
		loop(i,0,adj[u].size()){
			int v=adj[u][i].second;
			if(color[v]!=BLACK && d[v]>d[u]+adj[u][i].first){
				d[v]=d[u]+adj[u][i].first;
				pq.push(make_pair(d[v],v));
				color[v]=GRAY;
			}
		}
	}
}

C++: #include <stdio.h>
#include <vector>
#include <utility>
#define rep(i, n) for(int i = 0; i < n; ++i)
using namespace std;

typedef long long ll;

int main(void) {
  int n;
  scanf("%d", &n);
  ll dis[n];
  rep(i, n) dis[i] = 10e13;
  dis[0] = 0;
  vector< pair<int, int> > vec[n];
  rep(i, n) {
    int u, k;
    scanf("%d%d", &u, &k);
    rep(j, k) {
      int c, v;
      scanf("%d%d", &v, &c);
      pair<int, int> p = make_pair(v, c);
      vec[u].push_back(p);
    }
  }
  /*rep(i, n) {
    vector< pair<int, int> >::iterator it;
    for(it = vec[i].begin(); it != vec[i].end(); ++it) printf("%d:%d ", (*it).first, (*it).second);
    printf("\n");
  }*/
  rep(i, n - 1) {
    rep(j, n) {
      vector< pair<int, int> >::iterator it;
      for(it = vec[j].begin(); it != vec[j].end(); ++it) {
        if(dis[(*it).first] > dis[j] + (*it).second) dis[(*it).first] = dis[j] + (*it).second;
      }
    }
    /*rep(j, n) printf("%d ", dis[j]);
    printf("\n");*/
  }
  rep(i, n) printf("%d %lld\n", i, dis[i]);
  return 0;
}

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

typedef struct{
  int A[10005];
  long long ans;
  bool c;
}node;
node T[10005];
int Q[100000000];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
    if(head==99999999)head=1;
    T[num].c=true;
    for(int i=0;i<n;i++){
      if(T[num].A[i]!=0){
	if(T[i].ans>T[num].ans+T[num].A[i]){
	  T[i].ans=T[num].ans+T[num].A[i];
	Q[tail++]=i;
	if(tail==99999999)tail=1;
	}
      }
    }
  }
}

int main(){
  int num,son,z,w;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>num>>son;
    T[num].ans=INT_MAX;
    for(int j=0;j<son;j++){
      cin>>z>>w;
      T[num].A[z]=w;
      }
  }
  Q[0]=0;
  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}