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<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<20);
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] = INFTY;
        color[i] = INFTY;
    }

    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() {
    int k, u, v, c;

    cin >> n;
    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<queue>
using namespace std;
const int MAXn=10000;
const int INFTY=1<<21;

int n,col[MAXn],d[MAXn];
vector<pair<int,int>> Q[MAXn];

void dijkstra(int s)
{
	priority_queue<pair<int,int>> PQ;//weight,id
	for(int i=0;i<n;i++)
	{
		d[i]=INFTY;
		col[i]=0;
	}
	d[s]=0;
	PQ.push(make_pair(0,s));
	col[s]=1;
	
	while(!PQ.empty())
	{
		pair<int,int> f=PQ.top();PQ.pop();
		int u=f.second;
		col[u]=2;
		if(d[u]<f.first*(-1))continue;
		for(int j=0;j<Q[u].size();j++)
		{
			int v=Q[u][j].first;
			if(col[v]==2)continue;
			if(d[u]+Q[u][j].second<d[v])
			{
				d[v]=d[u]+Q[u][j].second;
				PQ.push(make_pair(d[v]*(-1),v));
				col[v]=1;
			}
		}
	}
	
	for(int i=0;i<n;i++)cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
	
	return;
}

int main() {
	cin>>n;int id,k,c,v;
	for(int i=0;i<n;i++)
	{
		cin>>id>>k;
		for(int j=0;j<k;j++)
		{
			cin>>v>>c;
			Q[id].push_back(make_pair(v,c));
		}
	}
	dijkstra(0);
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<cstring>
#include<queue>
#include<vector>
#define WHITE 0
#define BLACK 1
#define GRAY 2
using namespace std;
const int MAXN = 10000 + 4;
const int INF = 0x3f3f3f3f;
int status[MAXN], d[MAXN];
int N;
vector< pair<int, int> > ADJ[MAXN];
void Dijkstra (  )
{
    priority_queue< pair<int, int> > PQ;
    memset( status, WHITE, sizeof(status) );
    for ( int i = 0; i < N; i++ ) d[i] = INF;
    d[0] = 0;
    status[0] = GRAY;
    PQ.push(make_pair(0, 0));

    while ( !PQ.empty() ) {
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        status[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 ( status[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));
                status[v] = GRAY;
            }
        }
    }
    for ( int i = 0; i < N; i++ ) {
        cout<<i<<' '<<( d[i] == INF ? -1 : d[i] )<<endl;
    }
}

int main()
{
    int u, D, c, v;
    cin>>N;
    for ( int i = 0; i < N; i++ ) {
        cin>>u>>D;
        for ( int j = 0; j < D; j++ ) {
            cin>>v>>c;
            ADJ[u].push_back(make_pair(v, c));
        }
    }

    Dijkstra();
    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<20);
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] = 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(){
  int k,u,v,c;

  cin >> n;
  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;
}