Go: package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
	"container/heap"
)

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

C++: #include <algorithm>
#include <iostream>
#include <queue>
#include <vector>
using namespace std;
static const int NMAX = 100;
#define INF (1 << 30)

int main() {
  int n;
  cin >> n;
  vector<pair<int, int>> adj[NMAX];

  for (int i = 0; i < n; i++) {
    int id, nn;
    cin >> id >> nn;
    for (int j = 0; j < nn; j++) {
      int to, weight;
      cin >> to >> weight;
      // use negative weights for priority_queue
      adj[id].push_back(make_pair(-weight, to));
    }
  }

  bool visited[n];
  int dist[n];
  for (int i = 0; i<n; i++) {
    visited[i] = false;
    dist[i] = -INF;
  }

  priority_queue<pair<int, int>> distQ;

  // add node 0
  for (int i = 0; i < adj[0].size(); i++) {
    distQ.push(adj[0][i]);
    int weight = adj[0][i].first;
    int id = adj[0][i].second;
    dist[id] = weight;
  }
  visited[0] = true;

  while (!distQ.empty()) {
    // find nearest node
    int minnode = distQ.top().second;
    distQ.pop();

    // add node
    visited[minnode] = true;

    // update dist
    for (int i = 0; i < adj[minnode].size(); i++) {
      int weight = adj[minnode][i].first;
      int id = adj[minnode][i].second;

      if (visited[id] == false) {
        int newWeight = dist[minnode] + weight;
        if (-newWeight < -dist[id]) {
          distQ.push(make_pair(newWeight, id));
          dist[id] = newWeight;
        }
      }
    }
  }

  dist[0] = 0;
  for (int i = 0; i < n; i++)
    cout << i << " " << -dist[i] << endl;
}

C++: //
// Created by ?????°?????? on 2016/05/19.
//

#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
const int MAX = 100;
const int INFTY = (1<<21);
const int WHITE = 0;
const int GRAY = 1;
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 (){
    cin >> n;
    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;
            adj[u].push_back(make_pair(v,c));
        }
    }

    dijkstra();

    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(long long i=0; i<(n); i++)
#define int long long
#define mod 1000000007
#define F first
#define S second
#define P pair<long long,long long>
#define all(a) a.begin(),a.end()
#define INF 1000000000000000000
using namespace std;
struct edge{
    long long to;
    long long cost;
};
signed main(void){
    int n;cin>>n;
    vector<edge>G[n];
    int f,t,c,k;
    rep(i,n){
        cin>>f>>k;
        rep(j,k){
            cin>>t>>c;
            G[f].push_back({t,c});
        }
    }
    vector<int>d(n,INF);d[0]=0;
    //rep(i,n){
      //  rep(j,G[i].size()){
        //    cout<<G[i][j].to<<':'<<G[i][j].cost<<' ';
        //}
        //cout<<endl;
    //}
    priority_queue<P,vector<P>,greater<P>>que;
    que.push(P(0,0));
    while(!que.empty()){
        f=que.top().S;c=que.top().F;que.pop();
        if(d[f]<c)continue;
        rep(i,G[f].size()){
            edge e=G[f][i];
            t=e.to;
            if(d[t]>e.cost+c){
                d[t]=e.cost+c;
                que.push(P(d[t],t));
            }
        }
    }
    rep(i,n){
        cout<<i<<' '<<d[i]<<endl;
    }
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<21);

enum Color {
  WHITE, GRAY, BLACK
};

vector<pair<int, int> > adj[MAX];
int d[MAX];
Color color[MAX];
int n;

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

void dijkstra(int s) {
  init();
  d[s] = 0;
  priority_queue<pair<int, int> > PQ;
  PQ.push(make_pair(0, s));

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


int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    int elem, index, v;
    cin >> v >> elem;
    for (int j = 0; j < elem; j++) {
      int u, cost;
      cin >> u >> cost;
      adj[v].push_back(make_pair(u, cost));
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; i++) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}