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<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);

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);
	loop(i,0,n){
		d[i]=inf;
	}
	
	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][v].first){
				d[v]=d[u]+adj[u][i].first;
				pq.push(make_pair(d[v],v));
				color[v]=GRAY;
			}
		}
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
#define MAX 105
#define INFTY INT_MAX
 
int n, G[MAX][MAX];
 
void dijkstra() {
    int d[MAX], color[MAX];
    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[i] = 0;
    }
    d[0] = 0;
    while (1) {
        int u = -1;
        int minv = INFTY;
        for (int i = 0; i < n; i++) {
            if (color[i] != 1 && d[i] < minv) {
                minv = d[i];
                u = i;
            }
        }
        if (minv == INFTY)
            break;
        color[u] = 1;
        for (int v = 0; v < n; v++) {
            if (color[v] != 1 && G[u][v] != INFTY) {
                if (d[u] + G[u][v] < d[v])
                    d[v] = d[u] + G[u][v];
            }
        }
    }
    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }
}
 
int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            G[i][j] = INFTY;
        }
    }
    int k, v, c;
    for (int i = 0; i < n; i++) {
        cin >> k >> k;
        while (k--) {
            cin >> v >> c;
            G[i][v] = c;
        }
    }
    dijkstra();
    return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <queue>
#include <list>
using namespace std;

class Node
{
private:
	list<int> next_node_list;
	list<int> next_weight_list;
public:
	Node();
	void AddNextNode(int id, long weight);
	void SetWeight(int weight);
	void DistributeWeight();
	long weight_from_0;
	bool check;
};

Node::Node()
{
	weight_from_0 = -1;
	check = false;
}

Node *Node_list;

struct GreatNode
{
	bool operator()(const Node *n1, const Node *n2) const;
};
bool GreatNode::operator()(const Node *n1, const Node *n2) const
{
	return n1->weight_from_0 > n2->weight_from_0;
}
priority_queue<Node*, vector<Node*>, GreatNode > que;

void Node::AddNextNode(int id, long weight)
{
	next_node_list.push_back(id);
	next_weight_list.push_back(weight);
}

void Node::SetWeight(int weight)
{
	if (weight_from_0 == -1 || weight < weight_from_0) {
		weight_from_0 = weight;
	}
}

void Node::DistributeWeight()
{
	check = true;
	list<int>::iterator itr2 = next_weight_list.begin();
	for(list<int>::iterator itr = next_node_list.begin(); itr != next_node_list.end(); itr++){	
		if (Node_list[*itr].check == false) {
			Node_list[*itr].SetWeight(weight_from_0 + *itr2);
			que.push(&Node_list[*itr]);
		}
		itr2++;
	}
	next_node_list.clear();
	next_weight_list.clear();
}

int main(void)
{
	//input
	int n;
	cin >> n;
	Node_list = new Node[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;
			Node_list[i].AddNextNode(v, c);
		}
	}

	//weight from 0 ?
	Node_list[0].check = true;
	Node_list[0].weight_from_0 = 0;
	Node_list[0].DistributeWeight();
	while (!que.empty()) {
		Node *node = que.top();
		que.pop();
		node->DistributeWeight();
	}

	//output
	for (int i = 0; i < n; i++) {
		cout << i << " " << Node_list[i].weight_from_0 << endl;
	}
	
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define sz(x) int(x.size())
#define ALL(c) (c).begin(), (c).end()
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v, x) (std::find(v.begin(), v.end(), x) != v.end())

using namespace std;
typedef long long ll;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
const int INF = 1001001001;
const long long INFL = (1LL<<60);
const double eps = (1e-9);

typedef pair<int, int> P;

// @param [in] n: ノード数
// @param [in] cost: 重みの隣接表現
// @param [in] s: スタートするノード
// @param [out] d: s からの距離
void dijkstra(const int& n, const vector<vector<pair<int, int>>>& cost, const int& s, vector<int>& d) {
  priority_queue<P, vector<P>, greater<P>> que;  // P#first が小さい順に取り出せる
  d[s] = 0;
  que.push(P(0, s));

  while (!que.empty()) {
    P p = que.top(); que.pop();
    int v = p.second;
    if (d[v] < p.first) continue;
    for (int j = 0; j < cost[v].size(); j++) {  // v から移動できる全ての node について
      int t = cost[v][j].first;
      int c = cost[v][j].second;
      if (d[t] > d[v] + c) {
        d[t] = d[v] + c;
        que.push(P(d[t], t));
      }
    }
  }
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n;
  cin >> n;
  vector<vector<pair<int, int>>> cost(n);

  rep(i, n) {
    int u, k;
    cin >> u >> k;
    vector<pair<int, int>> tmp(k);
    rep(j, k) {
      int v, c;
      cin >> v >> c;
      tmp[j] = make_pair(v, c);
    }
    cost[i] = tmp;
  }

  // 求めるのは 0 からの距離
  vector<int> d(n, INF);
  dijkstra(n, cost, 0, d);

  rep(i, n) {
    cout << i << " " << d[i] << endl;
  }

  return 0;
}