Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const BIG_COST = 200000

type Path struct {
	node int
	cost int
}

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

	nNodes := scanInt(sc)

	// 各頂点につながる頂点一覧を得るための隣接リスト
	graph := make([][]Path, nNodes)

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[i] = make([]Path, k)
		for d := 0; d < k; d++ {
			graph[u][d] = Path{
				node: scanInt(sc),
				cost: scanInt(sc),
			}
		}
	}

	// 0 から各頂点への最小コストを保存する配列
	minCosts := make([]int, nNodes)

	minCosts[0] = 0
	for i := 1; i < nNodes; i++ {
		minCosts[i] = BIG_COST
	}

	// 各頂点が調査済みかどうかを保持する配列
	checked := make([]bool, nNodes)

	// 最小コストのパスを高速に取得するためのヒープ。
	// コストが小さいものほどルートに来るようにする。
	heap := NewHeap(func(a, b Path) bool {
		return a.cost < b.cost
	})

	heap.insert(Path{node: 0, cost: 0})
	for heap.size > 0 {
		u := heap.extractMax()

		// 隣接行列を使っていた時とは違い、ヒープには
		// 同じノードへのパスが複数含まれうる。そのため既によりコストの低い
		// パスが見つかっている場合は無視する。
		if minCosts[u.node] < u.cost {
			continue
		}

		checked[u.node] = true

		for _, v := range graph[u.node] {
			cost := v.cost + u.cost
			if !checked[v.node] && cost < minCosts[v.node] {
				minCosts[v.node] = cost
				heap.insert(Path{node: v.node, cost: cost})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range minCosts {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

// --- From ALDS1_9_C: Priority Queue

type Heap struct {
	size   int
	heap   []Path
	isHigh func(a, b Path) bool
}

func NewHeap(isHigh func(a, b Path) bool) Heap {
	heap := make([]Path, 1) // 先頭は不使用
	return Heap{size: 0, heap: heap, isHigh: isHigh}
}

func (h *Heap) insert(v Path) {
	h.size += 1
	if h.size > len(h.heap)-1 {
		h.heap = append(h.heap, v)
	} else {
		h.heap[h.size] = v
	}

	for i := h.size; i > 1; {
		parent := i / 2
		if h.isHigh(h.heap[parent], h.heap[i]) {
			break
		}
		h.heap[i], h.heap[parent] = h.heap[parent], h.heap[i]
		i = parent
	}
}

func (h *Heap) extractMax() Path {
	if h.size <= 0 {
		panic("cannot extract from empty heap")
	}

	max := h.heap[1]
	h.heap[1] = h.heap[h.size]
	h.size -= 1
	h.maxHeapify(1)

	return max
}

func (h *Heap) maxHeapify(idx int) {
	left := idx * 2
	right := left + 1
	largest := idx

	if left <= h.size {
		if h.isHigh(h.heap[left], h.heap[idx]) {
			largest = left
		}
		if right <= h.size && h.isHigh(h.heap[right], h.heap[largest]) {
			largest = right
		}
	}

	if largest != idx {
		h.heap[idx], h.heap[largest] = h.heap[largest], h.heap[idx]
		h.maxHeapify(largest)
	}
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;

const int  MAXN = 15000; //本机运行时修改数值 
const int IFNTY = 1 << 20;


void show(pair<int, int> p);
void dijkstra(vector< pair<int, int> > adj_list[], int n, int u, int dis[]);

int main()
{

	vector< pair<int,int> > adj_list[MAXN];
	
	int n;
	cin >> n;
	
	int u, k, v, c;;	
	for (int i = 0; i < n; i++)
	{
		cin >> u >> k;
		for (int j = 0; j < k; j++)
		{
			cin >> v >> c;
			adj_list[u].push_back(make_pair(v,c));
		}		
	}
	
//	for (int i = 0; i < n; i++)
//	{
//		cout << i << "   ";
//		for_each (adj_list[i].begin(), adj_list[i].end(), show);
//		cout << endl;
//	}

	
	int dis[MAXN];
	
	dijkstra(adj_list, n, 0, dis);
	
	for (int i = 0; i < n; i++)
	{
		cout << i << ' ' << dis[i] << endl;
	}

}


void show(pair<int, int> p)
{
	cout << p.first << ' ' << p.second << ' ';
}


void dijkstra(vector< pair<int, int> > adj_list[], int n, int u, int dis[])
{
	int visited[MAXN] = {0};
	priority_queue< pair<int, int> > pri_queue;
	
	for (int v = 0; v < n; v++)
 		dis[v] = IFNTY;
 		
	dis[u] = 0;
	pri_queue.push(pair<int, int>(0, u));
	
	while (!pri_queue.empty())
	{
		pair<int, int> p = pri_queue.top();
		pri_queue.pop();
		
		visited[p.second] = true;
		
		if (dis[p.second] < p.first * -1) continue; //如果是已经更新过的结点则跳过
		
		for (int i = 0; i < adj_list[p.second].size(); i++)
		{
			pair<int, int> v = adj_list[p.second][i];
//			if(visited[v.first]) continue;
			if (dis[v.first] > dis[p.second] + v.second)
			{
				dis[v.first] = dis[p.second] + v.second;
				pri_queue.push(pair<int, int>(dis[v.first] * -1, v.first));
			}
		} 
	} 
	
	
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
static const int MAX = 10000;
static const int INF = (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];
    for(int i=0; i<n; i++){
        d[i] = INF;
        color[i] = WHITE;
    }

    d[0] = 0;
    PQ.push(make_pair(0, 0));
    color[0] = WHITE;
    
    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] == INF ? -1 : d[i]) << endl;
    }
}




int main() 
{
    ios::sync_with_stdio(false);
    
    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<iostream>
#include<cstring>
#include<algorithm>
using namespace std;

int x[1000][1000];
int y[1000];

int main() {
	memset(x, 1, sizeof(x));
	memset(y, 1, sizeof(y));
	int n, a, b, c, d;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a >> b;
		for (int i = 0; i < b; i++) {
			cin >> c >> d;
			x[a][c] = d;
		}
	}
	y[0] = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			for (int k = 0; k < n; k++) {
				y[k] = min(y[k], y[j] + x[j][k]);
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << ' ' << y[i] << endl;
	}
	return 0;
}

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

static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int MAX=10000;
static const int INFTY=(1<<20);

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

void dijkstra(){
  
  priority_queue<pair<int, int> > PQ;
  int i,j,u,color[MAX],d[MAX],v;
  
  for(i=0;i<n;i++){
   
    color[i]=WHITE;
    d[i]=INFTY;
  }
   color[0]=GRAY;
  d[0]=0;
  PQ.push(make_pair(0,0));
 

  while(!PQ.empty()){
    pair<int, int> f=PQ.top();  PQ.pop();
  
    u=f.second;
    color[u]=BLACK;
    
    if(d[u]<f.first*(-1))continue;

    for(j=0;j<adj[u].size();j++){
      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++){
    cout<<i<<" "<<(d[i] == INFTY ? -1:d[i])<<endl;

  }
  
}

int main(){
  int i,k,u,v,c,j;

  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;
}