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<iomanip>
#include<algorithm>
#include<bitset>
#include<cassert>
#include<cctype>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<functional>
#include<limits>
#include<list>
#include<map>
#include<numeric>
#include<set>
#include<stack>
#include<string>
#include<sstream>
#include<queue>
#include<vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MOD 1000000007
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL

#define MAX 100

using Weight = int;
struct Edge {
	int s; //source
	int d; //destination
	Weight w; //weight
	Edge(int s = 0, int d = 0, int w = INF) : s(s), d(d), w(w) {};
};
using Edges = vector<Edge>;
//???????????\???
//g[u].push_back(Edge(u, v, c));
using Graph = vector<Edges>;
using Array = vector<Weight>;
using Matrix = vector<Array>;

//?????¢?´¢, ??¢?´¢???, ??¢?´¢???
enum { WHITE, GRAY, BLACK };

//???????§????????????? (Dijkstra)
//?????????: ??????????????§????????¢
vector<Weight> dijkstra(Graph g, int s) {
	typedef pair<Weight, int> State; //?§?????????????????°?????????? ??????id
	priority_queue<State, vector<State>, greater<State> >PQ;
	vector<int> color(g.size(), WHITE);
	vector<Weight> dist(g.size(), INF); //distance
	dist[s] = 0; PQ.push(State(0, s)); color[s] = GRAY; //?§????
	while (!PQ.empty()) {
		Weight d; int v;
		tie(d, v) = PQ.top(); PQ.pop(); //dist???????°??????¨??????????´????????????????	
		if (dist[v] < d) continue; //?????§???????????§???????????°??????
		color[v] = BLACK;
		for (auto e : g[v]) { //??£??\????????????????????¨????????????		
			if (color[e.d] == BLACK)continue; //??¢?´¢????????????
			if (dist[e.d] > dist[v] + e.w) {
				dist[e.d] = dist[v] + e.w;
				PQ.push(State(dist[e.d], e.d));
				color[e.d] = GRAY;
			}
		}
	}
	return dist;
}

int main() {
	int n; cin >> n;
	Graph 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(Edge(u, v, c));
		}
	}
	vector<Weight> ans = dijkstra(g, 0);
	for (int i = 0; i < n; i++) {
		cout << i << " " << ans[i] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#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];
  int i,j;
  for(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(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(i=0;i<n;i++){
    if(d[i]==INFTY)
      d[i]=-1;
    cout << i << " " << d[i];
    printf("\n");
  }
    
}
int main(void){
  int i,j;
  int k,v,c,u;
  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;
}