Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

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;
}