Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
)

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	route := make([][]Node, n)
	weight := make([]int, n)
	for i := 0; i < n; i++ {
		weight[i] = NIL
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		route[i] = make([]Node, k)
		for j := 0; j < k; j++ {
			route[u][j] = Node{id: scanInt(), weight: scanInt()}
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for _, nextNode := range route[node.id] {
			if weight[nextNode.id] != NIL {
				continue
			}
			nextNode.weight += node.weight
			heap.Push(h, nextNode)
		}
	}

	for i, w := range weight {
		fmt.Println(i, w)
	}
}

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;

}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
using namespace std;
static const int N = 10000;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int,int>> adj[N];

void dijkstra(int s){
	priority_queue<pair<int,int>> PQ;
	int color[N];
	int d[N];
	for(int i=0;i<n;i++){
		color[i] = WHITE;
		d[i] = INFTY;
	}
	d[s] = 0;
	PQ.push(make_pair(s,0));
	color[s] = 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(){
	cin >> n;
	int u,k,v,c;
	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(0);
	return 0;
}