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 <vector>
#include <queue>
using namespace std;
static const int MAX=10000;
static const int INFTY=(1<<21);
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]=INFTY; color[i]=WHITE;}
    d[0]=0;
    PQ.push(make_pair(0, 0));
    color[0]=GRAY;
    while(!PQ.empty()){
        pair<int,int> f=PQ.top(); PQ.pop();
        int u=f.second;
        color[u]=BLACK;
        if(d[u]<f.first*(-1)) continue;
        for(int j=0; j<adj[u].size(); j++){
            int v=adj[u][j].first;
            if(color[v]==BLACK)continue;
            if(d[v]>d[u]+adj[u][j].second){
                d[v]=d[u]+adj[u][j].second;
                PQ.push(make_pair(d[v]*(-1),v));
                color[v]=GRAY;
            }
        }
    }
    for(int i=0; i<n; i++) cout<<i<<" "<<(d[i]==INFTY ? -1: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<iostream>
#include<algorithm>
#include<queue>
using namespace std;
#define N 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2
static const int INFTY = (1<<20);
int n;
vector<pair<int,int> >adj[N];
void dijkstra(void);
int main()
{
  int i,j,k;
  int u, v, c;

  cin >> n;

  for(i = 0;i < n;i++)
  {
    cin >> u >> k;

    for(j = 0;j < k;j++)
    {
      cin >> v >> c;

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

  dijkstra();

  return 0;
}




void dijkstra()
{
  priority_queue<pair<int,int> >PQ;
  int i,j;
  int u,v;
  int d[N],color[N];

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

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

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

    u = a.second;
    color[u] = BLACK;

        if(d[u] < a.first*(-1))
        {
          continue;
        }

        for(j = 0;j < adj[u].size();j++)
        {
          v = adj[u][j].first;

          if(color[v] == BLACK)
          {
    	       continue;
          }

          if(d[v] > d[u] + adj[u][j].second)
          {
    	       color[v] = GRAY;
    	       d[v] = d[u] + adj[u][j].second;
    	       PQ.push(make_pair(d[v]*(-1),v));
          }
        }

      }

      for(i = 0;i < n;i++)
      {
        cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
      }
    }

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,N) for(ll i=0;i<N;++i)
typedef long long int ll;
ll INF = 900010;
static const int white = 0;
static const int gray = 1;
static const int black = 2;
using P = pair<int ,int>;

ll N;
vector<vector<P> > G(10010);

void dijkstra(){
    priority_queue<P, vector<P> , greater<P> > pq;
    vector<int> color(N,white);
    vector<int> d(N,INF);
    d[0] = 0;
    pq.push(make_pair(0,0));
    color[0] = gray;

    while(!pq.empty()){
        P f = pq.top(); pq.pop();
        int u = f.second;
        color[u] = black;

        if(d[u] > f.first ) continue;

        for(auto e : G[u]){
            int v = e.first;
            if( color[v] == black ) continue;
            if(d[v] > d[u] + e.second ){
                d[v] = d[u] + e.second;
                pq.push(make_pair(d[v], v));
                color[v] = gray;
            }
        }
    }

    rep(i,N){
        cout << i << " " << (d[i] == INF ? -1 : d[i] ) << endl;
    }
}

int main(){
    cin >> N;
    rep(j,N){
        ll u,k; cin >> u >> k;
        rep(i,k){
            ll v,c; cin >> v >> c;
            G[u].push_back(make_pair(v,c));
        }
    }

    dijkstra();
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using pii = pair<int, int>;
using vpii = vector<pii>;
using vvpii = vector<vpii>;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define WHITE 0
#define VISITED 1
#define CANDIDATE 2

void dks(vvpii &g, vi &d, vi &s) {
  priority_queue<pii, vpii, greater<pii>> q;
  q.push(make_pair(d[0], 0));

  while (!q.empty()) {
    auto qt = q.top(); q.pop();
    int u = qt.second, c = qt.first;
    s[u] = VISITED;

    if (d[u] < c) continue;
    
    for (auto cp: g[u]) {
      int v = cp.first, t = d[u] + cp.second;
      if (s[v] != VISITED && t < d[v]) {
        d[v] = t;
        s[v] = CANDIDATE;
        q.push(make_pair(d[v], v)); 
      }
    }
  }
}

int main() {
  int n;
  cin >> n;
  
  vvpii g(n);
  rep(_, n) {
    int u, k;
    cin >> u >> k;

    rep(__, k) {
      int v, c;
      cin >> v >> c;

      g[u].push_back(make_pair(v, c));
    }
  }
  
  vi d(n, 1 << 21), s(n, WHITE);
  d[0] = 0;
  dks(g, d, s);

  rep(i, n) printf("%d %d\n", i, d[i]);
}