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<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;
}