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 <algorithm>
#include <iostream>
#include <queue>
using namespace std;

static const int Max = 100;
static const int Inf = 10000;
enum State {
	Not_Searched = 0,
	Connected = 1,
	Searched = 2
};

int n = 0;
vector<pair<int, int> > adj[Max]; // pair<??£??\??????index, ??????cost> 

void dijkstra() {
	priority_queue<pair<int, int> > pq; // pair<start ???????????????????????????????????§????????????????´???????idx>
	int st[Max];
	int min_cost[Max];
	for (int i = 0; i < n; i++) {
		st[i] = Not_Searched;
		min_cost[i] = Inf;
	}

	min_cost[0] = 0;
	pq.push(make_pair(0, 0));
	st[0] = Connected;

	while (!pq.empty()) {
		pair<int, int> f = pq.top();
		pq.pop();
		int u = f.second;
		st[u] = Searched;

		if (min_cost[u] < f.first * (-1)) continue;

		for (int i = 0; i < adj[u].size(); i++) {
			int adj_u_idx = adj[u][i].first;
			if (st[adj_u_idx] == Searched) continue;
			if (min_cost[adj_u_idx] > min_cost[u] + adj[u][i].second) {
				min_cost[adj_u_idx] = min_cost[u] + adj[u][i].second;
				pq.push(make_pair(min_cost[adj_u_idx]*(-1), adj_u_idx));
				st[adj_u_idx] = Connected;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (min_cost[i] == Inf ? -1 : min_cost[i]) << endl;
	}
	return;
}

int main() {
	cin >> n;
	int u, k, vi, ci;
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> vi >> ci;
			adj[u].push_back(make_pair(vi, ci));
		}
	}

	dijkstra();
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<utility>
#include<limits>
using namespace std;
typedef pair<int, int> Edge;
int main()
{
	int n; cin >> n;
	vector< vector< Edge > > lists;

	for (int i = 0; i < n; i++)
	{
		vector<Edge> list;
		int u, k;
		cin >> u >> k;
		for (int j = 0; j < k; j++)
		{
			Edge edge;
			cin >> edge.second >> edge.first;
			list.push_back(edge);
		}
		lists.push_back(list);
	}

	vector<int> costs(n, INT32_MAX);
	costs[0] = 0;
	priority_queue<Edge> queue;
	for (Edge edge : lists[0])
		queue.push(edge);

	while (!queue.empty())
	{
		Edge edge = queue.top(); queue.pop();
		int dest = edge.second;
		int cost = edge.first;
		if (costs[dest] < cost)continue;
		int new_cost = costs[edge.second] = edge.first;

		for (Edge next : lists[dest])
		{
			next.first += new_cost;
			queue.push(next);
		}
	}
	for (int i = 0; i < n; i++)
		cout << i << " " << costs[i] << endl;

	char c;
	cin >> c;

	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 d[MAX],color[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,c,u,v;
  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>
#include<vector>
#define INF (int)1e9 + 7
using namespace std;
int n;
vector<pair<int, int> > adj[10000];
void dijkstra();
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c; //vertex cost
            cin >> v >> c;
            adj[u].push_back(make_pair(c, v));
        }
    }
    dijkstra();
    return 0;
}
void dijkstra() {
    int dist[n];
    dist[0] = 0;
    for (int i = 1; i < n; i++) {
        dist[i] = INF;
    }
    priority_queue<pair<int, int> > q;
    q.push(make_pair(0, 0));
    while (!q.empty()) {
        int u = q.top().second;
        int co = -q.top().first;
        q.pop();
        for (int i = 0; i < adj[u].size(); i++) {
            int v = adj[u][i].second;
            int co2 = adj[u][i].first;
            if (dist[u] + co2 < dist[v]) {
                dist[v] = co2 + dist[u];
                q.push(make_pair(-dist[v] ,v));
            }
        }
    }
    for (int i = 0; i < n; i++) {
        cout << i << " " << dist[i] << endl;
    }
    
}