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 <queue>
#include <algorithm>
#define MAX 1000
#define INF (1<<21)
#define WHITE 0
#define GRAY  1
#define BLACK 2
using namespace std;

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

void Dijkstra() 
{
    priority_queue<pair<int,int>> PQ;
    int next, min_cost;
    int color[n], dist[n];

    for (int i = 0; i < n; ++i) 
    {
        color[i] = WHITE;
        dist[i] = INF;
    }

    dist[0] = 0;
    PQ.push(make_pair(0, 0));
    color[0] = GRAY;

    while(! PQ.empty())
    {
        pair<int, int> next = PQ.top(); PQ.pop();
        int u = next.second;

        color[u] = BLACK;

        if (dist[u] < next.first * (-1)) continue;

        for (int i = 0; i < adj_list[u].size(); ++i) 
        {
            int v = adj_list[u][i].first;
            if (color[v] == BLACK) continue;
            if (dist[v] > dist[u] + adj_list[u][i].second)
            {
                color[v] = GRAY;
                dist[v] = dist[u] + adj_list[u][i].second;
                PQ.push(make_pair(dist[v]*(-1), v));
            }
        }
    }
    
    int sum = 0;
    for (int i = 0; i < n; ++i) 
    {
        cout << i << ' ' << (dist[i] != INF ? dist[i] : -1) << endl; 
    }
}

int main() 
{
    int id, deg, v, w;

    cin >> n;
    for (int i = 0; i < n; ++i) 
    {
        cin >> id >> deg;
        for (int j = 0; j < deg; ++j) 
        {
            cin >> v >> w;
            adj_list[id].push_back(make_pair(v, w));
        }
    }

    Dijkstra();

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<utility>
#include<limits>
using namespace std;
typedef pair<int, int> Edge;
const int MAX = 1000000000;
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, 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<queue>

#include<vector>
#include<utility>

using namespace std;

#define MAX 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 1<<21

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

void dijkstra(){
  priority_queue<pair<int,int> > PQ;
  
  for(int i=0;i<n;i++){
    color[i] = WHITE;
    d[i] = INFTY;
  }

  d[0] = 0;
  color[0] = GRAY;
  PQ.push(make_pair(d[0],0));

  while( !PQ.empty() ){
    pair<int, int> present = PQ.top();
    PQ.pop();

    int u = present.second;
    color[u] = BLACK;

    for(int j=0;j<adj[u].size();j++){
      int v = adj[u][j].first;
      if(color[v] != BLACK && d[v] > d[u] + adj[u][j].second ){
        d[v] = d[u] + adj[u][j].second;
        color[v] = GRAY;
        PQ.push(make_pair(-1*d[v], v));
      }   
    }
  }

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

}

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

  dijkstra();

  return 0;
}

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

using namespace std;
using graph = vector<vector<int>>;


int main() {
    int n;
    cin >> n;

    graph G(n, vector<int>(n, -1));
    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;
            G[u][v] = c;
        }
    }

    // Dijkstra's algorithm
    vector<int> d(n, -1);
    vector<bool> visited(n, false);

    d[0] = 0;
    visited[0] = true;
    while (1) {
        int u = -1;
        int v = -1;
        int minw = numeric_limits<int>::max();
        for (int i = 0; i < n; ++i) {
            if (!visited[i])
                continue;
            for (int j = 0; j < n; ++j) {
                if (visited[j] || G[i][j] < 0)
                    continue;
                int w = G[i][j] + d[i];
                if (w < minw) {
                    u = i;
                    v = j;
                    minw = w;
                }
            }
        }
        if (v < 0) {
            break;
        }
        d[v] = minw;
        visited[v] = true;
    }

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

    return 0;
}