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<cstdlib>
#include<queue>
#include<set>
#include<vector>
#include<string>
#include<algorithm>
#include<stack>
#include<map>
#include<cstdio>
#include<fstream>
using namespace std;
#define rep(i,a) for(int i=0;i<a;i++)

#define mp make_pair
#define P pair<int,int>
#define ll __int64
vector<P>G[20000];
int n,u,k;
const int INF=100000000;
int ans[20000];

int main(){
	int from,cost;
	cin>>n;

	rep(i,n){
		cin>>u>>k;
		rep(i,k){
				cin>>from>>cost;
				G[u].push_back(mp(from,cost));
		}
	}
	rep(i,n)ans[i]=INF;
	//ans[0]=0;
	priority_queue<P,vector<P>,greater<P> >que;//firstスタートからの重みsecond頂点
	que.push(mp(0,0));
	
	while(!que.empty()){
		P now=que.top();
		que.pop();
		if(ans[now.second]!=INF)continue;
		int index=now.second;
		ans[index]=now.first;
		//cout<<now.first<<endl;
		for(int i=0;i<G[now.second].size();i++)que.push(mp(now.first+G[index][i].second,G[index][i].first));//次への経路長、頂点番号
	}
	for(int i=0;i<n;i++)cout<<i<<" "<<ans[i]<<endl;
	return 0;
}

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

using namespace std;

static const int MAX = 10000;
static const int INF = 1 << 30;
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] = INF;
        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] == INF ? -1 : d[i]) << endl;
    }
}

int main()
{
    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 <algorithm>
#include <cstdio>
#include <cstring>
#include <vector>
#include <string>
#include <queue>
using namespace std;
const int INF = 1 << 30;
const int NIL = -1;
const int MAXN = 10005;
int graph[MAXN][MAXN];
int vis[MAXN];
int d[MAXN];
int n;
void dijkstra(int s)
{
	for (int i = 0; i < n; ++i)
	{
		vis[i] = false;
		d[i] = graph[0][i];
	}
	vis[s] = true;
	d[s] = 0;
	while (true)
	{
		int minicost = INF;
		int id = -1;
		for (int i = 0; i < n; ++i)
		{
			if (!vis[i] && minicost > d[i])
			{
				minicost = d[i];
				id = i;
			}
		}
		if (minicost == INF)
			break;
		vis[id] = true;
		for (int i = 0; i < n; ++i)
		{
			if (!vis[i] && d[i] > d[id] + graph[id][i])
				d[i] = d[id] + graph[id][i];
		}
	}
}

int main(void)
{
		
	int k, s, e, w;
	scanf("%d", &n);
	for (int i = 0; i < n; ++i)
		for (int j = 0; j < n; ++j)
			graph[i][j] = INF;
	for (int i = 0; i < n; ++i)
	{
		scanf("%d%d", &s, &k);
		while (k--)
		{
			scanf("%d %d", &e, &w);
			graph[s][e] = w;
		}
	}
	dijkstra(0);
	for (int i = 0; i < n; ++i)
		printf("%d %d\n", i, d[i]);

	return 0;
}

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

const int Max = 10000;
const int Infty = (1 << 21);
const int white = 0, gray = 1, black = 2;

int d[Max], color[Max];
int n;

vector<pair<int, int> > adj[Max];

void dijkstra(int s){
    priority_queue<pair<int, int> > PQ;
    for(int i=0; i<n; i++){
        d[i] = Infty;
        color[i] = white;
    }
    d[s] = 0;
    color[s] = gray;
    PQ.push(make_pair(0, 0)); //(d[u], u) u:be adjacent to s

    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 i=0; i<adj[u].size(); i++){
            int v = adj[u][i].first;
            if(color[v] == black) continue;
            if(d[u] + adj[u][i].second < d[v]){
                d[v] = d[u] + adj[u][i].second;
                color[v] = gray;
                PQ.push(make_pair(d[v] * (-1), v));
            }
        }
    }
    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 >> n >> k;
        for(int j=0; j<k; j++){
            cin >> v >> c;
            adj[u].push_back(make_pair(v, c));
        }
    }

    dijkstra(0);

    return 0;
}