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 <iostream> 
#include <queue>
#include <algorithm>
#define MAX 10000
#define INF (1<<21)
#define WHITE 0
#define GRAY  1
#define BLACK 2
using namespace std;

int n;
vector<pair<int, int>> adj_list[MAX];

void Dijkstra() 
{
    priority_queue<pair<int,int>> PQ;
    int next, min_cost;
    int color[n], dist[n];

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

    dist[0] = 0;
    PQ.push(make_pair(0, 0));
    color[0] = GRAY;

    while(! PQ.empty())
    {
        pair<int, int> next = PQ.top(); PQ.pop();
        int u = next.second;

        color[u] = BLACK;

        if (dist[u] < next.first * (-1)) continue;

        for (int i = 0; i < adj_list[u].size(); ++i) 
        {
            int v = adj_list[u][i].first;
            if (color[v] == BLACK) continue;
            if (dist[v] > dist[u] + adj_list[u][i].second)
            {
                color[v] = GRAY;
                dist[v] = dist[u] + adj_list[u][i].second;
                PQ.push(make_pair(dist[v]*(-1), v));
            }
        }
    }
    
    int sum = 0;
    for (int i = 0; i < n; ++i) 
    {
        cout << i << ' ' << (dist[i] != INF ? dist[i] : -1) << endl; 
    }
}

int main() 
{
    int id, deg, v, w;

    cin >> n;
    for (int i = 0; i < n; ++i) 
    {
        cin >> id >> deg;
        for (int j = 0; j < deg; ++j) 
        {
            cin >> v >> w;
            adj_list[id].push_back(make_pair(v, w));
        }
    }

    Dijkstra();

    return 0;
}

C++: #include <cstdio>
#include <queue>
#include <vector>
using namespace std;
#define INF 1 << 30
typedef pair<int, int> P;

int n, d[10000];
vector<P> M[10000];

void dijkstra(void) {
    int i, u, v;
    P t;
    priority_queue<P, vector<P>, greater<P> > pq;

    pq.push(make_pair(0, 0));
    while (!pq.empty()) {
        t = pq.top(); pq.pop();
        v = t.first;
        u = t.second;

        if (d[u] != INF) continue;
        d[u] = v;

        for (i = 0; i < M[u].size(); i++) {
            t = M[u][i];
            if (d[t.second] != INF) continue;
            pq.push(make_pair(v + t.first, t.second));
        }
    }
}

int main(void) {
    int i, j, u, k, v, c;
    scanf("%d", &n);

    for (i = 0; i < n; i++) d[i] = INF;

    for (i = 0; i < n; i++) {
        scanf("%d %d", &u, &k);
        for (j = 0; j < k; j++) {
            scanf("%d %d", &v, &c);
            M[u].push_back(make_pair(c, v));
        }
    }

    dijkstra();

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

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<cmath>
#include<vector>
using namespace std;

static const int MAX=1000;
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];
  int d[MAX];

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

  d[0]=0;
  PQ.push(make_pair(0,0));
  color[0]=GRAY;

  while(!PQ.empty()){
    int u;
    pair<int,int> f=PQ.top();
    PQ.pop();
    u=f.second;

    color[u]=BLACK;

    for(int i=0;i<adj[u].size();i++){
      int v=adj[u][i].first;
      if(color[v]==BLACK) continue;
      if(d[u]+adj[u][i].second<d[v]){
	d[v]=d[u]+adj[u][i].second;
	PQ.push(make_pair(d[v]*(-1),v));
	color[v]=GRAY;
      }
    }
  }

  for(int i=0;i<n;i++) cout<<i<<" "<<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();
  
  return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

vector<pair<int, int>> adja[10000];

#define INF (1 << 30)

int main() {
	int n, id, k, a, b;

	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		for (int j = 0; j < k; ++j) {
			cin >> a >> b;
			adja[id].push_back(make_pair(a, b));
		}
	}

	priority_queue<pair<int, int>> que;
	que.push(make_pair(0, 0)); //cost, node
	int cost[10000];
	fill(cost, cost + n, INF);

	while (!que.empty()) {
		for (int i = 0, size = que.size(); i < size; ++i) {
			pair<int, int> top = que.top();
			que.pop();

			if (cost[top.second] < top.first) {
				continue;
			}
			cost[top.second] = top.first;

			for (int j = 0, len = adja[top.second].size(); j < len; ++j) {
				que.push(make_pair(top.first + adja[top.second][j].second, adja[top.second][j].first));
			}
		}
	}

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

	return 0;
}