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<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define loop(i,a,b) for(i=a;i<b;i++)
#define rloop(i,a,b) for(i=a;i>=b;i--)
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
const int inf=1000000001;
const ll INF=1e16;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int N=10000;

int n;
vector< vector< pair<int,int> > > adj(N,vector< pair<int,int> >());
vi d(N,inf);

void dijkstra();

int main(){
	int k,u,v,c,i,j;
	cin>>n;
	loop(i,0,n){
		cin>>u>>k;
		loop(j,0,k){
			cin>>v>>c;
			adj[u].push_back(make_pair(c,v));
		}
	}
	dijkstra();
	loop(i,0,n){
		cout<<i<<" "<<((d[i]==inf)? -1:d[i])<<endl;
	}
}

void dijkstra(){
	priority_queue< pair<int,int>, vector< pair<int,int> >, greater< pair<int,int> > > pq;
	int i;
	vi color(n,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){
			continue;
		}
		loop(i,0,adj[u].size()){
			int v=adj[u][i].second;
			if(color[v]!=BLACK && d[v]>d[u]+adj[u][i].first){
				d[v]=d[u]+adj[u][i].first;
				pq.push(make_pair(d[v],v));
				color[v]=GRAY;
			}
		}
	}
}

C++: #include <stdio.h>
#include <vector>
#include <utility>
#define rep(i, n) for(int i = 0; i < n; ++i)
using namespace std;

typedef long long ll;

int main(void) {
  int n;
  scanf("%d", &n);
  ll dis[n];
  rep(i, n) dis[i] = 10e13;
  dis[0] = 0;
  vector< pair<int, int> > vec[n];
  rep(i, n) {
    int u, k;
    scanf("%d%d", &u, &k);
    rep(j, k) {
      int c, v;
      scanf("%d%d", &v, &c);
      pair<int, int> p = make_pair(v, c);
      vec[u].push_back(p);
    }
  }
  /*rep(i, n) {
    vector< pair<int, int> >::iterator it;
    for(it = vec[i].begin(); it != vec[i].end(); ++it) printf("%d:%d ", (*it).first, (*it).second);
    printf("\n");
  }*/
  rep(i, n - 1) {
    rep(j, n) {
      vector< pair<int, int> >::iterator it;
      for(it = vec[j].begin(); it != vec[j].end(); ++it) {
        if(dis[(*it).first] > dis[j] + (*it).second) dis[(*it).first] = dis[j] + (*it).second;
      }
    }
    /*rep(j, n) printf("%d ", dis[j]);
    printf("\n");*/
  }
  rep(i, n) printf("%d %lld\n", i, dis[i]);
  return 0;
}

C++: #include<iostream>
#include<climits>
using namespace std;

typedef struct{
  int A[10005];
  long long ans;
  bool c;
}node;
node T[10005];
int Q[100000000];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
    if(head==99999999)head=1;
    T[num].c=true;
    for(int i=0;i<n;i++){
      if(T[num].A[i]!=0){
	if(T[i].ans>T[num].ans+T[num].A[i]){
	  T[i].ans=T[num].ans+T[num].A[i];
	Q[tail++]=i;
	if(tail==99999999)tail=1;
	}
      }
    }
  }
}

int main(){
  int num,son,z,w;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>num>>son;
    T[num].ans=INT_MAX;
    for(int j=0;j<son;j++){
      cin>>z>>w;
      T[num].A[z]=w;
      }
  }
  Q[0]=0;
  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}