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<bits/stdc++.h>
#define F first
#define S second
using namespace std;
typedef pair<int,int>P;
typedef vector<P>VP;
int main(void){
	int n;
	int u,k,v,c;
	int i,j;
	VP vp[10001];
	bool flg[10001]={false};
	int d[10001];
	P pp;
	int x,y,cost,ncost;
	priority_queue<P,VP,greater<P>>que;
	int cnt;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>u>>k;
		for(j=0;j<k;j++){
			cin>>v>>c;
			vp[u].push_back(make_pair(c,v));
		}
	}
	que.push(make_pair(0,0));
	cnt=0;
	while(!que.empty()){
		pp=que.top();
		que.pop();
		cost=pp.F;
		x=pp.S;
		if(!flg[x]){
			flg[x]=true;
			d[x]=cost;
			cnt++;
			if(cnt==n)	break;
			for(i=0;i<vp[x].size();i++){
				y=vp[x][i].S;
				ncost=vp[x][i].F;
				if(!flg[y]){
					que.push(make_pair(cost+ncost,y));
				}
			}
		}
	}
	for(i=0;i<n;i++)	cout<<i<<" "<<d[i]<<endl;
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#define MAX 10000
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INF 11<<20
using namespace std;

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] = 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++){
		if(d[i] == INF)cout << i << " " << -1 <<endl;
		else cout << i << " " << d[i] << endl;
	}
}

int main(){
	int u,k,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 <bits/stdc++.h>
#define ll long long int
#define P pair<int,int>
struct edge{int to,cost;};
using namespace std;


class CompareDist
{
public:
    bool operator()(pair<int,int> n1,pair<int,int> n2) {
        return n1.second>n2.second;
    }
};

int V;
vector<vector<edge>> G;
vector<int> d;

void dijkstra(int s){
    priority_queue<P,vector<P>,CompareDist> q;
    //fill(d,d+V,INT_MAX);
    d=vector<int>(V,INT_MAX);
    d[s]=0;
    q.push(P(0,s));
    
    while(!q.empty()){
        P p=q.top();q.pop();
        int v=p.first;
        if(d[v]<p.second)continue;
        for(int i=0;i<G[v].size();i++){
            edge e=G[v][i];
            if(d[e.to]>d[v]+e.cost){
                d[e.to]=d[v]+e.cost;
                q.push(P(e.to,d[e.to]));
            }
        }
    }
}
int main(void){
    int n,in,t,c;
    cin>>n;
    V=n;
    G.resize(n);
    d.resize(n);
    for(int i=0;i<n;i++){
        cin>>in;
        int node=in;
        cin>>in;
        for(int j=0;j<in;j++){
            cin>>t>>c;
            G[node].emplace_back((edge){t,c});
        }
        
    }
    dijkstra(0);
    for(int i=0;i<d.size();i++){
        cout<<i<<" "<<d[i]<<endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

const long long INFF = 1e18;

const int MAX_N = 11000;
using TYPE = long long; // ?????¢???????????\??????
vector<pair<int, TYPE> > G[MAX_N];

vector<TYPE> dijkstra(int start){
	vector<TYPE> dist(MAX_N, INFF);
	dist[start] = 0;//dist[i] :=???start->i?????§??????????????¢
	priority_queue<pair<TYPE, int>, vector<pair<TYPE, int> >, greater<pair<TYPE, int> > >  que;
	que.push(make_pair(0, start));
	while(!que.empty()){
		TYPE cost; int u;//????????§???????????£????????? ?????¨?????????
		cost = que.top().first, u = que.top().second;
		que.pop();
		if(dist[u] < cost) continue;
		dist[u] = cost;
		for (auto tmp : G[u]){
			int v = tmp.first; TYPE time = tmp.second;//??£??\???????????? ?????????????????§????????????
			if(dist[v] > dist[u] + time){//u->v
				// if(dist[v] != INFF) printf("%f %fa\n", dist[v], dist[u] + time);
				// dist[v] = dist[u] + time;
				que.push(make_pair(dist[u] + time, v));
			}
		}
	}
	return dist;
}


int main(void) {
	int n; cin >> n;
	rep(q, n) {
		int u, k; cin >> u >> k;
		vector<int> v(k); vector<long long> c(k);
		rep(i, k) cin >> v[i] >> c[i];
		rep(i, k) G[u].push_back(make_pair(v[i], c[i]));
	}
	auto dist = dijkstra(0);
	rep(i, n) printf("%d %d\n", i, dist[i]);
	return 0;
}

C++: #include <iostream>
#include <queue>
#include <algorithm>
#include <vector>
#include <climits>
#define int long long
using namespace std;
typedef pair <int,int> P;
#define to first
#define co second
#define fi first
#define se second
const int INF=INT_MAX;
const int MAX_V=100000;
vector <P> G[MAX_V];
int v,d[MAX_V];

void dijk(int s){
  priority_queue <P,vector<P>,greater<P> > que;
  fill(d,d+v,INF);
  d[s]=0;
  que.push(P(0,s));
  for(;!que.empty();){
    P p=que.top(); que.pop();
    int v=p.se;
    if (d[v]<p.fi) continue;
    for(int i=0;i<(int)G[v].size();i++){
      P e=G[v][i];
      if(d[e.to]>d[v]+e.co){
        d[e.to]=d[v]+e.co;
        que.push(P(d[e.to],e.to));
      }
    }
  }
}
signed main(){
  cin>>v;
  for(int i=0,u,k;i<v&&cin>>u>>k;i++) for(int j=0,a,b;j<k&&cin>>a>>b;j++) G[u].push_back(P(a,b));
  dijk(0);
  for(int i=0;i<v;i++) cout<<i<<" "<<d[i]<<endl;
  return 0;

}