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<stdio.h>
#include<stdlib.h>
struct node{
  int key;
  int cost;
  struct node *next;
};
typedef struct node *GG;
  
GG G[10001];
GG MNode(int,int,GG);
void Insert(int,int,int);
int main()
{
  int i,j,n,count=0,v,c,c1,v1;
  int color[10001],d[10001],pi[10001],mincost,ii;
  GG GGG;
  scanf("%d",&n);
  for(i=0;i<n;i++)G[i]=MNode(0,0,NULL);
  for(i=0;i<n;i++){
    scanf("%d%d",&v,&c);
    for(j=0;j<c;j++){
      scanf("%d%d",&v1,&c1);
      Insert(i,v1,c1);
    }
  }
  for(i=0;i<n;i++){
    color[i]=0;
    pi[i]=-1;
    d[i]=10000001;
  }
  d[0]=0;
   
  while(1){
    mincost=10000001;
    for(i=0;i<n;i++){
      if(color[i]!=2 && d[i]<mincost){
        mincost=d[i];
        ii=i;
      }
    }
    if(mincost==10000001)break;
    color[ii]=2;
    for(GGG=G[ii];GGG!=NULL;GGG=GGG->next){
      if(color[GGG->key]!=2 && (GGG->cost+d[ii])<d[GGG->key]){
    pi[GGG->key]=ii;
    d[GGG->key]=GGG->cost+d[ii];
    color[GGG->key]=1;
      }
    }
  }
  for(i=0;i<n;i++)printf("%d %d\n",i,d[i]);
   
  return 0;
}
  
GG MNode(int key,int cost,GG Node)
{
  GG n;
  n=(GG)malloc(sizeof(struct node));
  n->key=key;
  n->cost=cost;
  n->next=Node;
  return n;
}
void Insert(int s,int t,int u)
{
  GG GGG;
  GGG=MNode(t,u,G[s]->next);
  G[s]->next=GGG;
}

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

using namespace std ;
typedef long long ll;
typedef string str;
typedef pair<int, int> pii;
typedef vector<int> vint;
typedef vector<double> vdou ;
typedef vector<ll> vll;
typedef vector<vint> vvint;
typedef vector<str> vstr;
typedef pair<ll,ll> pll ;
typedef vector<pii> vpii ;
typedef vector<pll> vpll ;

#define REP(i, n) for (ll (i) = 0; (i) < (ll)(n); i++) 
#define FOR(i, a, b) for(ll (i) = a; (i) < (ll)b; i++)
#define ALL(v) (v).begin(),(v).end()
#define MOD 1000000007
#define CHI 1000000000000000003
#define NIL -1
#define FI first
#define SE second
#define MP make_pair
#define PB push_back
#define SZ(x)  (ll)x.size()
#define SP(x)  setprecision((ll)x)

const int INF = 1e9;
const ll LINF = 1e18;
const double EPS = 1e-9;
const double PI = M_PI;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
ll gcd(ll a, ll b) {return b ? gcd(b, a % b) : a;} //最大公約数
ll lcm(ll a, ll b) {return a / gcd(a, b) * b;} //最小公倍数

void yes(){
  cout <<"Yes"<<endl ;
}
void no(){
  cout <<"No"<<endl ;
}
//-----------------------------------------

const int MAX_V = 1e5 ;

struct edge{
    int to, cost ;
    //iからの行き先とそのコストの情報
};

int n ;
vector<edge> G[MAX_V] ;
//G[i]...iからの行き先(to)とコスト(cost)の情報を持つ
int d[MAX_V] ;
//d[i]...sからiへ行くのにかかるコストの最小

int par[MAX_V] ;
//par[i]...iの一個前

void dijkstra(int s){
    priority_queue<pii,vpii,greater<pii> > que ;
    //pair<sからiへ行くのの暫定最小コスト、i>の優先度付きキュー
    REP(i,n){
        d[i] = INF ;
      	par[i] = i ;
        //はじめコストはINFで初期化
    }
    d[s] = 0 ;
    que.push(MP(0,s)) ;
    //自身へのコストは0としてqueへ入れる
    
    while(!que.empty()){
        pii p = que.top() ;
        que.pop() ;
        int v = p.SE ;
        
        if(d[v] < p.FI){
            continue ;
        }
        REP(i,SZ(G[v])){
            //vを経由した行き先について
            edge e = G[v][i] ;
            if(d[e.to]>d[v]+e.cost){
                d[e.to] = d[v] + e.cost ;
                par[v] = e.to ;
                que.push(MP(d[e.to],e.to)) ;
            }
        }
    }
}








//-----------------------------------------
int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n ;
  REP(i,n){
      int a, k ;
      cin >> a >> k  ;
      REP(j,k){
          int b, c ;
          cin >> b >> c ;
          edge e = {b,c} ;
          G[a].PB(e) ;
      }
  }
  
  dijkstra(0) ;
  
  REP(i,n){
      cout << i <<" "<<d[i] <<endl;
  }

  return 0 ;
}

C++: //
//  main.cpp
//
//
//  Created by ???????????? on 2017/10/23.
//  Copyright ?? 2017 ????????????. All rights reserved.
//

#include <iostream>
#include <stdio.h>
#include <queue>
#include <algorithm>


#define n_max 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 1<<20

using namespace std;

int n, M[n_max][n_max], color[n_max], d[n_max], p[n_max];

void init(){
    int i, j, id, num, node;
    scanf("%d", &n);
    for(i = 0; i < n; i++){
        for(j = 0; j < n; j++){
            M[i][j] = INFTY;
        }
    }
    
    
    for(i = 0; i < n; i++){
        scanf("%d %d", &id, &num);
        for(j = 0; j < num; j++){
            scanf("%d", &node);
            scanf("%d", &M[id][node]);
        }
        color[i] = WHITE;
        d[i] = INFTY;
    }
}

void dijkstra(){
    //initializing
    d[0] = 0;
    p[0] = -1;
    
    priority_queue<pair<int, int>> PQ;
    
    PQ.push(make_pair(0, 0));
    
    int u;
    while(!PQ.empty()){
        //first weight, second idx
        pair<int, int> f= PQ.top(); PQ.pop();
        u = f.second;
        color[u] = BLACK;
        
        if(d[u] < f.first*(-1)) continue;
        
        for(int v = 0; v < n; v++){
            if((color[v] != BLACK) && (M[u][v] != INFTY)){
                if((d[u] + M[u][v]) < d[v]){
                    d[v] = M[u][v] + d[u];
                    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 argc, const char * argv[]) {
    init();
    dijkstra();
    return 0;
}