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 <vector>
#include <queue>
using namespace std;
#define INF 1e9
typedef pair<int, int> pi;
int used[10100];
int dist[10100];

int main() {
  int n;
  cin >> n;
  
  // first:weight, second:key
  priority_queue<pi, vector<pi>, greater<pi>> pqueue;
  // graph[from][to], first:key, second:distance
  vector<vector<pi>> graph(n);
  
  for (int i = 0; i < n; i++) {
    dist[i] = INF;
  }
  for (int i = 0; i < n; i++) {
    int u, k;
    cin >> u >> k;
    vector<pi> vec(k);
    int v, c;
    for (int j = 0; j < k; j++) {
      cin >> v >> c;
      vec[j] = make_pair(v, c);
    }
    graph[i] = vec;
  }

  pqueue.push(make_pair(0,0));
  dist[0] = 0;
  
  for (int i = 0; i < n; i++) {
    pi p = pqueue.top();
    pqueue.pop();
    int key = p.second;
    if (used[key] == 1) {
      i--;
      continue;
    }
    dist[key] = min(dist[key], p.first);
    used[key] = 1;
    for (int j = 0; j < graph[key].size(); j++) {
      if (used[graph[key][j].first] != 1) {
        int d = graph[key][j].second + dist[key];
        pqueue.push(make_pair(d, graph[key][j].first));
      }
    }
  }

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

C++: #include <iostream>
#include<cstdlib>
#include<queue>
#include<set>
#include<vector>
#include<string>
#include<algorithm>
#include<stack>
#include<map>
#include<cstdio>
#include<fstream>
using namespace std;
#define rep(i,a) for(int i=0;i<a;i++)

#define mp make_pair
#define P pair<int,int>
#define ll __int64
vector<P>G[20000];
int n,u,k;
const int INF=100000000;
int ans[20000];

int main(){
	int from,cost;
	cin>>n;

	rep(i,n){
		cin>>u>>k;
		rep(i,k){
				cin>>from>>cost;
				G[u].push_back(mp(from,cost));
		}
	}
	rep(i,n)ans[i]=INF;
	//ans[0]=0;
	priority_queue<P,vector<P>,greater<P> >que;//firstスタートからの重みsecond頂点
	que.push(mp(0,0));
	
	while(!que.empty()){
		P now=que.top();
		que.pop();
		if(ans[now.second]!=INF)continue;
		int index=now.second;
		ans[index]=now.first;
		//cout<<now.first<<endl;
		for(int i=0;i<G[now.second].size();i++)que.push(mp(now.first+G[index][i].second,G[index][i].first));//次への経路長、頂点番号
	}
	for(int i=0;i<n;i++)cout<<i<<" "<<ans[i]<<endl;
	return 0;
}

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

using namespace std;

static const int MAX = 10000;
static const int INF = 1 << 30;
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 d[MAX], color[MAX];

    for (int i = 0; i < n; ++i){
        d[i] = INF;
        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] == INF ? -1 : d[i]) << endl;
    }
}

int main()
{
    cin >> n;
    int k, c, u, v;
    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 <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <vector>
#include <string>
#include <queue>
using namespace std;
const int INF = 1 << 30;
const int NIL = -1;
const int MAXN = 10005;
int graph[MAXN][MAXN];
int vis[MAXN];
int d[MAXN];
int n;
void dijkstra(int s)
{
	for (int i = 0; i < n; ++i)
	{
		vis[i] = false;
		d[i] = graph[0][i];
	}
	vis[s] = true;
	d[s] = 0;
	while (true)
	{
		int minicost = INF;
		int id = -1;
		for (int i = 0; i < n; ++i)
		{
			if (!vis[i] && minicost > d[i])
			{
				minicost = d[i];
				id = i;
			}
		}
		if (minicost == INF)
			break;
		vis[id] = true;
		for (int i = 0; i < n; ++i)
		{
			if (!vis[i] && d[i] > d[id] + graph[id][i])
				d[i] = d[id] + graph[id][i];
		}
	}
}

int main(void)
{
		
	int k, s, e, w;
	scanf("%d", &n);
	for (int i = 0; i < n; ++i)
		for (int j = 0; j < n; ++j)
			graph[i][j] = INF;
	for (int i = 0; i < n; ++i)
	{
		scanf("%d%d", &s, &k);
		while (k--)
		{
			scanf("%d %d", &e, &w);
			graph[s][e] = w;
		}
	}
	dijkstra(0);
	for (int i = 0; i < n; ++i)
		printf("%d %d\n", i, d[i]);

	return 0;
}