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>

using namespace std;

#define MAX 100
#define NIL (1<<21)
#define WHITE 0
#define GRAY 1
#define BLACK 2

int m[MAX][MAX],n;
int color[MAX];
int d[MAX];

void visit(){
    int minv;
    for(int i = 0; i < n; i++){
        color[i] = WHITE;
        d[i] = NIL;
    }
    color[0]=GRAY;
    d[0] = 0;
    while(1){
        minv = NIL;
        int u = -1;
        for(int i = 0; i < n; i++){
            if(minv > d[i] && color[i] != BLACK){
                u = i;
                minv = d[i];
            }
        }
        if(u == -1){
            break;
        }
        color[u]=BLACK;
        for(int v = 0; v < n; v++){
            if(color[v] != BLACK && m[u][v] != NIL){
                if(d[v]>d[u]+m[u][v]){
                    d[v] = d[u] + m[u][v];
                    color[v] = GRAY;
                }
            }
        }
    }
    for (int i = 0; i < n; i++){
        cout << i << " " << (d[i] == NIL?-1:d[i]) << endl;
    }
}

int main(){
    cin >> n;
    for (int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            m[i][j] = NIL;
        }
    }
    int k, c, u, v;
    for(int i = 0; i < n; i++){
        cin >> u >> k;
        for(int j = 0;j < k; j++){
            cin >> v >> c;
            m[u][v] = c;
        }
    }
    visit();
    return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
using namespace std;
#define MAX_VAL 110000
#define INF 4123456789123456

typedef long long ll;
typedef pair<ll,ll> P;

struct edge{ll to, cost;};

vector<edge> G[MAX_VAL];
ll d[MAX_VAL], V;

void dijkstra(ll s){
	priority_queue<P,vector<P>,greater<P>> q;
	fill(d,d+V, INF);
	
	d[s] = 0;
	q.push(P(0,s));
	
	while(!q.empty()){
		P p = q.top();q.pop();
		ll v = p.second;
		
		if(d[v] < p.first) continue;
		
		for(edge e : G[v]){
			if(d[e.to] > d[v] + e.cost){
				d[e.to] = d[v] + e.cost;
				q.push(P(d[e.to],e.to));
			}
		}
	}
	
	
}

int main(){
	int u, k, v, c;
	cin>>V;
	
	for(int i = 1; i <= V; i++){
		cin>>u>>k;
		for(int j = 1; j <= k; j++){
			cin>>v>>c;
			edge  e = {v,c};
			G[u].push_back(e);
		}
	}
		dijkstra(0);
	for(int i = 0; i < V; i++){
		cout<<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n,M[MAX][MAX];

void dijkstra()
{
  int minv;
  int d[MAX],color[MAX];

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

  d[0] = 0;
  color[0] = GRAY;
  while(1)
  {
    minv = INFTY;
    int u = -1;
    for(int i=0;i<n;i++)
    {
      if(minv > d[i] && color[i] != BLACK)
      {
        u = i;
        minv = d[i];
      }
    }
    if(u == -1) break;
    color[u] = BLACK;
    for(int v = 0; v<n;v++)
    {
      if(color[v] != BLACK && M[u][v] != INFTY)
      {
        if(d[v]>d[u] + M[u][v])
        {
          d[v] = d[u]+M[u][v];
          color[v] = GRAY;
        }
      }
    }
  }
  for(int i=0;i<n;i++)
  {
    cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
  }
}

int main()
{
  cin >> n;
  for(int i=0;i<n;i++)
  {
    for(int j=0;j<n;j++)
    {
      M[i][j] = INFTY;
    }
  }

  int k,c,u,v;
  for(int i=0;i<n;i++)
  {
    cin >> u >> k;
    for(int j=0;j<k;j++)
    {
      cin >> v >> c;
      M[u][v] = c;
    }
  }

  dijkstra();
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
#define INF 2e9
using namespace std;

void Dikstra(const vector<vector<pair<int, int> > >& G, vector<int>& d){
    d[0] = 0;
    priority_queue<pair<int, int> , vector<pair<int, int> >, greater<pair<int, int> > > PQ;
    PQ.push(make_pair(0, 0));
    vector<bool> is_black(d.size(), false);
    is_black[0] = true;
    while (!PQ.empty()) {
        int t = PQ.top().second;
        PQ.pop();
        is_black[t] = true;
        for (int i = 0; i < G[t].size(); i++) {
            int v = G[t][i].first;
            int w = G[t][i].second;
            if (!is_black[v] && d[t] + w < d[v]) {
                bool flag = false;
                d[v] = d[t] + w;
                PQ.push(make_pair(d[v], v));
            }
        }
    }

}

int main(){
    int n;
    cin >> n;
    vector<vector<pair<int, int> > > G(n);
    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;
            G[u].push_back(make_pair(v, c));
        }
    }
    vector<int> d(n, INF);
    Dikstra(G, d);
    for (int i = 0; i < n; i++) {
       cout << i << " " << d[i] << endl;
    }

    return 0;
}