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 <cstdio>
#include <set>
#include <algorithm>
#include <cstring>

#define INF 1000000
using namespace std;

struct edge
{
  int to, nxt, w;
};

edge E[500005];
int head[10005], cnt = 0, dist[10005];
void add_edge(int u, int v, int w)
{
  E[cnt].to = v;
  E[cnt].w = w;
  E[cnt].nxt = head[u];
  head[u] = cnt++;
}

void dijkstra(int src)
{
  set <pair <int, int> > setds;
  for (int i = 0; i < 10005; i++)
  {
    dist[i] = INF;
  }
  setds.insert(make_pair(0, src));
  dist[src] = 0;
  while (!setds.empty())
  {
    pair<int, int> tmp = *(setds.begin());
    setds.erase(setds.begin());
    int u = tmp.second;
    for (int e = head[u]; ~e; e = E[e].nxt)
    {
      int v = E[e].to;
      int w = E[e].w;
      if (dist[v] > dist[u] + w)
      {
        if (dist[v] != INF)
        {
          setds.erase(setds.find(make_pair(dist[v], v)));
        }
        dist[v] = dist[u] + w;
        setds.insert(make_pair(dist[v], v));
      }
    }
  }
}

int main()
{
  memset(head, -1, sizeof(head));

  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
  {
    int v, deg;
    scanf("%d%d", &v, &deg);
    for (int j = 0; j < deg; j++)
    {
      int to, cost;
      scanf("%d%d", &to, &cost);
      add_edge(v, to, cost);
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; i++)
  {
    printf("%d %d\n", i, dist[i]);
  }
}

C++: #include <cstdint>
#include <vector>

using namespace std;

#define GRAPH_SIZE 100
#define WEIGHT_MAX 100001

enum state_t {
  WHITE,
  GRAY,
  BLACK,
};

static uint32_t graph[GRAPH_SIZE][GRAPH_SIZE];
static state_t state[GRAPH_SIZE];
static uint32_t dist[GRAPH_SIZE];

size_t single_source_shotest_path(size_t num)
{
  size_t cost = 0;

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

  state[0] = GRAY;
  dist[0] = 0;

  while (true) {
    size_t minimum_cost = WEIGHT_MAX;
    uint32_t to = 0;
    for (uint32_t i = 0; i < num; i++) {
      if ((dist[i] < minimum_cost) && (state[i] != BLACK)) {
        minimum_cost = dist[i];
        to = i;
      }
    }

    if (minimum_cost == WEIGHT_MAX) break;

    cost += minimum_cost;
    state[to] = BLACK;

    for (uint32_t i = 0; i < num; i++) {
      if (((dist[to] + graph[to][i]) < dist[i]) && state[i] != BLACK) {
        state[i] = GRAY;
        dist[i] = dist[to] + graph[to][i];
      }
    }
  }

  return cost;
}

#include <iostream>

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

  for (uint32_t i = 0; i < num; i++) {
    for (uint32_t j = 0; j < num; j++) {
      graph[i][j] = WEIGHT_MAX;
    }
  }

  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 v, c;
      cin >> v >> c;
      graph[index][v] = c;
    }
  }

  single_source_shotest_path(num);

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

  return 0;
}