Go: package main

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

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

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;
}

C++: /#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;

map <int,int> mp;

#define INF (1<<30)
#define INFLL (1ll<<60)
#define EPS (1e-10)
static const int MAX=1e5;
static const int MOD=1e9+7;
static const int NMAX=50;
static const int MMAX=50;
int dx[4]={0,1,0,-1},dy[4]={-1,0,1,0};

typedef pair<int, int> P; //最短距離,頂点の番号
struct edge{
    int to,cost;
};
int N;
vector<edge> G[MAX]; //
int d[MAX]; //最短距離

void dijkstra(int s){
    priority_queue<P, vector<P>,greater<P> > que;
    
    fill(d,d+N,INF);
    d[s]=0;
    que.push(P(0,s));
    
    while(!que.empty()){
        P p=que.top(); que.pop();
        int v=p.second;
        
        if(d[v] < p.first) 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;
                que.push(P(d[e.to],e.to));
            }
        }
    }
}


int main(){
    cin.tie(0);  ios::sync_with_stdio(false);
    
    int k,u;
    cin>>N;
    for(int i=0;i<N;i++){
        cin>>u>>k;
        for(int j=0;j<k;j++){
            edge e;
            cin>>e.to>>e.cost;
            G[u].push_back(e);
        }
    }
    dijkstra(0);
    for(int i=0;i<N;i++)
        cout<<i<<" "<<(d[i]==INF?-1:d[i])<<"\n";
    
    return 0;
    }