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 <queue>
#include <stdint.h>
#include <vector>

typedef void (*single_source_shortest_path_callback_t)(int32_t index, int32_t weight);

#define GRAPH_MAX_SIZE 10000
enum color_t { WHITE, GRAY, BLACK };

static int32_t weights[GRAPH_MAX_SIZE];
static color_t colors[GRAPH_MAX_SIZE];

bool single_source_shortest_path(vector<pair<int32_t, int32_t>> *graph, size_t size, single_source_shortest_path_callback_t callback)
{
  if ((graph == nullptr) || (size == 0)) return false;

  int32_t i;
  for (i = 0; i < GRAPH_MAX_SIZE; i++) {
    weights[i] = INT32_MAX;
    colors[i] = WHITE;
  }

  weights[0] = 0;
  priority_queue<pair<int32_t, int32_t>> que;
  que.push(make_pair(-1 * weights[0], 0));

  while (!que.empty()) {
    pair<int, int> top = que.top();
    que.pop();
    int32_t top_index = top.second;
    int32_t top_weights = (-1) * top.first;
    if (top_weights > weights[top_index]) continue;

    callback(top_index, top_weights);
    colors[top_index] = BLACK;

    vector<pair<int32_t, int32_t>> vertex = graph[top_index];
    for (auto connect_to = vertex.begin(); connect_to != vertex.end(); connect_to++) {
      int32_t index = (*connect_to).first;
      if (colors[index] != BLACK) {
        int32_t new_weight = weights[top_index] + (*connect_to).second;

        if (new_weight < weights[index]) {
          weights[index] = new_weight;
          colors[index] = GRAY;
          que.push(make_pair(-1 * weights[index], index));
        }
      }
    }
  }
  return true;
}

#if !defined(TEST)
static vector<pair<int32_t, int32_t>> graph[GRAPH_MAX_SIZE];
static int32_t routes[GRAPH_MAX_SIZE];

void callback(int32_t index, int32_t weight)
{
  routes[index] = weight;
}

int32_t main(void)
{
  int32_t num;
  scanf("%d", &num);

  uint32_t i;
  for (i = 0; i < num; i++) {
    int32_t index, len;
    scanf("%d", &index);
    scanf("%d", &len);
    uint32_t j;
    for (j = 0; j < len; j++) {
      int32_t k, v;
      scanf("%d %d", &k, &v);
      graph[i].push_back(make_pair(k, v));
    }
  }
  single_source_shortest_path(graph, num, callback);

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

  return 0;
}
#endif

C++: #include <iostream>
#include <string>
#include <cstring>
#include <fstream>
#include <cmath>
#include <iomanip>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>
#include <deque>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <list>
#include <unordered_map>

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(){
    priority_queue <pair<int,int>> PQ;
    int color[MAX],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(){
    
    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();
}