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<map>
#include<list>
#include<cmath>
#include<stack>
#include<queue>
#include<vector>
#include<cstring>
#include<iostream>
#include<functional>
#include<algorithm>
using namespace std;
#define LOOP1(n) for(int i=0;i<n;i++)
#define LOOP2(n) for(int j=0;j<n;j++)
#define LOOP3(n) for(int k=0;k<n;k++)
#define Psi pair<string,int>
#define Pis pair<int,string>
#define Pii pair<int,int>
// ??????????????????memset(a,0,sizeof(a));
// ?´???°?????? if(x<2)return0;else if(x==2)return1;if(x%2==0)return0;for(i=3;i*i<=x;i+=2){if(x%i==0)return0;}return1;}p440
//vector size();push_back(x);pop_back();begin();end();insert(p,x);erase(p);clear();
//stack  size();top();pop();push(x);emtpy();
//queue  size();front();pop();push(x);empty();
//priority_queue< ??? , ??\???????????? , less<???> or greater<???> > <int , vector<int> , greater<int> >
/*******************************************/
/* vector<int> v     vector<int> v[100]    */
/* ???[1]          ?????? [1,1][1,2][1,3]     */
/*   [2]               [2,1][2,2][3,3]     */
/*   [3]               [3,1][2,2][3,3]     */
/*******************************************/
static const int MAX = 10000;
static const int WHITE = 1;
static const int GRAY = 2;
static const int BLACK = 3;
static const int INFTY = (1 << 21);
int d[MAX]; int color[MAX]; 
int main(){
	vector<pair<int, int>> v[MAX];
	int n, k, uu;
	cin >> n;
	for (int i = 0; i < n; i++){
		cin >> uu >> k;
		for (int j = 0; j < k; j++){
			Pii p;
			cin >> p.first >> p.second;
			v[i].push_back(p);
		}
	}
	for (int i = 0; i < n; i++){
		d[i] = INFTY;
		color[i] = WHITE;
	}
	d[0] = 0; int u = 0;
	while (1){
		int mincost = INFTY;
		LOOP1(n){
			if (color[i] != BLACK && mincost > d[i]){
				mincost = d[i];
				u = i;
			}
		}
		if (mincost == INFTY) break;
		color[u] = BLACK;
		for (int j = 0; j < v[u].size(); j++){
			if (color[v[u][j].first] != BLACK && d[u] + v[u][j].second < d[v[u][j].first]){
				color[v[u][j].first] = GRAY;
				d[v[u][j].first] = d[u] + v[u][j].second;
			}
		}
	}
	LOOP1(n){
		cout << i << ' ' << d[i] << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<list>
#define INF 2e9
using namespace std;

void Dikstra(const vector<vector<pair<int, int> > >& G, vector<int>& d){
    d[0] = 0;
    list<int> i_gray;
    i_gray.push_back(0);
    vector<bool> is_black(d.size(), false);
    is_black[0] = true;
    while (!i_gray.empty()) {
        list<int>::iterator min_it = i_gray.begin();
        for (list<int>::iterator it = i_gray.begin(); it != i_gray.end(); it++) {
            if (d[*it] < d[*min_it]) min_it = it;
        }
        is_black[*min_it] = true;
        for (int i = 0; i < G[*min_it].size(); i++) {
            int v = G[*min_it][i].first;
            int w = G[*min_it][i].second;
            if (!is_black[v] && d[*min_it] + w < d[v]) {
                if (d[v] == INF) i_gray.push_back(v);
                d[v] = d[*min_it] + w;
            }
        }
        i_gray.erase(min_it);
    }
}

int main(){
    int n;
    cin >> n;
    vector<vector<pair<int, int> > > G(n);
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c;
            cin >> v >> c;
            G[u].push_back(make_pair(v, c));
        }
    }
    vector<int> d(n, INF);
    Dikstra(G, d);
    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }

    return 0;
}