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>
#include<functional>
#define MAX 10000
#define INFTY (1<<20)
#define MPII(a,b) make_pair((a),(b))
#define PII pair<int,int>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i<(n);i++)
using namespace std;

class Node
{
public:
	Node() {};
	int d;
	bool done;
	priority_queue<PII, vector<PII>, greater<PII>> E;
};

int main()
{
	queue<int> order;
	Node nodes[MAX];
	REP(i, MAX)
	{
		nodes[i].done = false;
		nodes[i].d = INFTY;
	}
	int n;
	cin >> n;
	FOR(i, 0, n)
	{
		int ID, m;
		cin >> ID >> m;
		REP(l, m)
		{
			int v, w;
			cin >> v >> w;
			PII p = MPII(w, v);
			nodes[ID].E.push(p);
		}
	}
	int now = 0;
	order.push(now);
	nodes[now].d = 0;
	while (1)
	{
		if (nodes[now].done == false)
		{
			while (!nodes[now].E.empty())
			{
				PII temp = nodes[now].E.top();
				nodes[now].E.pop();
				int nextv = temp.second;
				order.push(nextv);
				int w = temp.first;
				if (nodes[nextv].d > nodes[now].d + w)
				{
					nodes[nextv].d = nodes[now].d + w;
				}
			}
			nodes[now].done = true;
		}
		order.pop();
		if (order.empty())break;
		now = order.front();
	}
	REP(i, n)
	{
		cout << i << " " << nodes[i].d << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <climits>
#include <vector>
using namespace std;
typedef unsigned short ushort;

class blanch{
	public:
		bool visited;
		int distance;
		ushort from;
		ushort to;
};
typedef vector <blanch> vb;
typedef vector <vb> vvb;

int make_graph(vvb &graph, vb &nodes){

	int n=nodes.size();
	for (ushort i=0; i<n; i++){
		nodes[i].visited = false;
		nodes[i].distance = INT_MAX;
	}

	for (ushort i=0; i<n; i++){
		int i2, n2;
		cin>>i2;
		cin>>n2;

		blanch bl0;
		bl0.visited = false;
		bl0.from = i2;

		for (ushort j=0; j<n2; j++){
			ushort j2;
			cin>>bl0.to;
			cin>>bl0.distance;

			graph[i2].push_back(bl0);
		}
	}
	return 0;
}

int Shortest_Path(vvb &graph, vb &nodes){

	int n = graph.size(), p1=0;
	nodes[p1].distance = 0;
	int p2;
	while (p1 != -1){
		nodes[p1].visited=true;
		for (int i = 0; i < (int)graph[p1].size(); i++){
			blanch tmp = graph[p1][i];
			p2=tmp.to;
			if (nodes[p2].visited==false){
				int tmp2 = tmp.distance + nodes[p1].distance;
				if (tmp2 < nodes[p2].distance){
					tmp.distance = tmp2;
					nodes[p2] = tmp;
				}
			}
		}
		p1 = -1;
		int tmp;
		tmp = INT_MAX;
		for (int i=0; i<n; i++){
			if (nodes[i].visited==false && nodes[i].distance<tmp){
				p1 = i;
				tmp = nodes[i].distance;
			}
		}
	}
	return 0;
}

int resultout(vb &nodes){
	int n = nodes.size();
	for (int i=0; i<n; i++){
		cout<<i<<" "<<nodes[i].distance<<endl;
	}
	return 0;
}

int main(void){

	int n;
	cin>>n;
	vvb G(n, vb());
	vb nodes(n);

	make_graph(G, nodes);

	Shortest_Path(G, nodes);

	resultout(nodes);
	G.clear();
	nodes.clear();

	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;
			if(costs[next.second]==INT_MAX)
				queue.push(next);
		}
	}
	for (int i = 0; i < n; i++)
		cout << i << " " << costs[i] << endl;

	char c;
	cin >> c;

	return 0;
}