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 <cstdint>
#include <queue>
#include <vector>

using namespace std;

#define GRAPH_SIZE 10000
#define WEIGHT_MAX UINT32_MAX

enum state_t { WHITE, GRAY, BLACK };

static state_t state[GRAPH_SIZE];
static priority_queue<pair<uint32_t, uint32_t>, vector<pair<uint32_t, uint32_t>>, greater<pair<uint32_t, uint32_t>>> min_queue;
static vector<pair<uint32_t, uint32_t>> graph[GRAPH_SIZE];
static uint32_t dist[GRAPH_SIZE];

void single_source_shortest_path(size_t num)
{
  for (uint32_t i = 0; i < num; i++) {
    // dist[i] = WEIGHT_MAX;
    state[i] = WHITE;
  }

  state[0] = GRAY;
  min_queue.push(make_pair(0, 0));

  while (!min_queue.empty()) {
    pair<uint32_t, uint32_t> vertex = min_queue.top();
    min_queue.pop();
    if (state[vertex.first] != BLACK) {
      state[vertex.first] = BLACK;
      dist[vertex.first] = vertex.first;

      for (uint32_t i = 0; i < graph[vertex.first].size(); i++) {
        pair<uint32_t, uint32_t> to = graph[vertex.first][i];
        if (state[vertex.first] != BLACK) {
          min_queue.push(make_pair(vertex.first, vertex.second + to.second));
          state[vertex.first] = GRAY;
        }
      }
    }
  }
}

#include <iostream>

int32_t main()
{
  uint32_t num;
  cin >> num;

  for (uint32_t i = 0; i < num; i++) {
    uint32_t index, len;
    cin >> index >> len;
    for (uint32_t j = 0; j < len; j++) {
      uint32_t connect, weight;
      graph[index].push_back(make_pair(connect, weight));
    }
  }

  single_source_shortest_path(num);

  for (uint32_t i = 0; i < num; i++) {
    cout << i << " " << dist[i] << endl;
  }

  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#define MAX 10000
#define INF (1<<30)

using namespace std;
enum state{
  BLACK,
  WHITE
};

int main(){
  vector<pair<int,int>> a[MAX];
  int n; cin>>n;
  int d[MAX];
  state s[MAX];

  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;
      a[u].push_back(make_pair(v,c));
    }
  }

  for(int i=0;i<n;i++){
    s[i]=WHITE;
    d[i]=INF;
  }
  d[0]=0;

  priority_queue<pair<int,int>> q;
  q.push(make_pair(0,0));

  while(!q.empty()){
    pair<int,int> p;
    p = q.top(); q.pop();
    if(s[p.second]==BLACK) continue;
    d[p.second]=p.first*-1;
    s[p.second]=BLACK;
    
    for(auto it = a[p.second].begin(); it!=a[p.second].end(); it++){
      int i = it->first;
      int cost = it->second;
      if(s[i]==WHITE && d[i] > d[p.second] + cost ){
        d[i]=d[p.second]+cost;
        q.push(make_pair(d[i]*-1,i));
      }
    }
  }
  
  for(int i=0;i<n;i++){
    printf("%d %d\n",i,d[i]);
  }


}

C++: #include <iostream>
#include <queue>
#include <utility>
#include <vector>

#define MAX_NODE 10000
#define INF 1000000000

using namespace std;

struct Edge {int to, w;};
typedef pair<int, int> PII;

vector<Edge> adj[MAX_NODE];
int d[MAX_NODE];

void dijkstra(int n, int start) {
	priority_queue<PII, vector<PII>, greater<PII>> que;
	fill(d, d + n, INF);

	d[start] = 0;
	que.emplace(0, start);
	while (!que.empty()) {
		PII p = que.top();
		que.pop();
		int from = p.second;

		if (d[from] < p.first)
			continue;

		for (auto& e : adj[from])
			if (d[from] + e.w < d[e.to]) {
				d[e.to] = d[from] + e.w;
				que.emplace(d[e.to], e.to);
			}
	}
}

int main() {
	ios::sync_with_stdio(false);
	std::cin.tie(NULL);

	int n;

	cin >> n;

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		while (k--) {
			int v, c;
			cin >> v >> c;
			adj[u].push_back({v, c});
		}
	}

	dijkstra(n, 0);

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

	return 0;
}