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 <bits/stdc++.h>

using weight = int;

struct edge {
    int to;
    weight cost;
};

using edges = std::vector<edge>;
using graph = std::vector<edges>;

// when g has neg cycle, second -> false
std::pair<std::vector<weight>, bool> spfa(graph const& g, int s) {
    constexpr weight inf = std::numeric_limits<weight>::max() / 2;
    const int n = g.size();
    std::vector<weight> d(n, inf);
    std::vector<int> in_q(n), count(n);
    std::queue<int> que;
    d[s] = 0;
    que.emplace(s);
    in_q[s] = true;
    ++count[s];
    bool neg_cycle = false;
    [&]() {
        while(!que.empty()) {
            int v = que.front();
            que.pop();
            in_q[v] = false;
            for(auto& e : g[v]) {
                if(d[v] != inf && d[e.to] > d[v] + e.cost) {
                    d[e.to] = d[v] + e.cost;
                    if(!in_q[e.to]) {
                        que.emplace(e.to);
                        in_q[e.to] = true;
                        ++count[e.to];
                        if(count[e.to] >= n) {
                            neg_cycle = true;
                            return;
                        }
                    }
                }
            }
        }
    }();

    return std::make_pair(d, !neg_cycle);
}

using namespace std;

int main() {
    int n;
    cin >> n;
    graph g(n);
    for(int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        for(int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            g[u].push_back(edge{v, c});
        }
    }

    auto ans = spfa(g, 0).first;
    for(int i = 0; i < n; ++i) {
        cout << i << ' ' << ans[i] << endl;
    }
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int maxx=10010;
const int infinity=1<<30;

int main() {
	int n,a,b,c,e;
	vector<pair<int, int> > A[maxx];
	bool flag[maxx];
	int d[maxx];
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>a>>b;
		for(int j=0;j<b;j++){
			cin>>c>>e;
			A[a].push_back(make_pair(c,e));
		}
	}
	for(int i=0;i<n;i++){
		flag[i]=false;
		d[i]=infinity;
	}
	priority_queue<pair<int,int> > PQ;
	d[0]=0;
	PQ.push(make_pair(0, 0));
	while(PQ.empty()==0){
		pair<int, int> u=PQ.top();
		PQ.pop();
		//cout<<u.first<<" "<<d[u.first]<<endl;
		flag[u.second]=true;
		int len=A[u.second].size();
		for(int i=0;i<len;i++){
			int v=A[u.second][i].first;
			if(flag[v]==false && d[u.second]+A[u.second][i].second<d[v]){
				d[v]=d[u.second]+A[u.second][i].second;
				PQ.push(make_pair(d[v]*(-1),v));
			}
		}
	}

	for(int i=0;i<n;i++) cout<<i<<" "<<(d[i]==infinity ? -1 : d[i])<<endl;

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n) ; i++)
constexpr auto INF = 2147483647;
typedef long long ll;

static const int MAX = 10000;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int,int>> Adj_vec[MAX];

void dijkstra(){
  priority_queue<pair<int,int>> pq;
  int color[MAX], d[MAX];
  rep(i,n){
    color[i] = WHITE;
    d[i] = INF;
  }
  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_vec[u].size(); j++){
      int v = Adj_vec[u][j].first;
      if(color[v] == BLACK) continue;
      if(d[v] > d[u] + Adj_vec[u][j].second){
        d[v] = d[u] + Adj_vec[u][j].second;
        pq.push(make_pair(d[v] * -1, v));
        color[v] = GRAY;
      }
    }
  }
  rep(i,n){
    cout << i << " " << (d[i] == INF ? -1 : d[i]) << endl;
  }
}

int main(){
  int k, c, u, v;
  cin >> n;
  rep(i,n){
    cin >> u >> k;
    rep(j,k){
      cin >> v >> c;
      Adj_vec[u].push_back(make_pair(v, c));
    }
  }

  dijkstra();

  return 0;
}

C++: #include <iostream>
#include <vector> 
#include <algorithm>
#include <queue>
#include <cstdio> 
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<21);
int d[MAX],color[MAX];
int n;
vector<pair<int, int> > adj[MAX];

void dijkstra()
{
    priority_queue<pair<int, int> > PQ;
    for (int i = 0; i < n; i++)
    {
        d[i] =INFTY;
        color[i] = 0;
    } 
    d[0] = 0;
    PQ.push(make_pair(0,0));
    color[0] = 1;
    while (!PQ.empty())
    { 
        pair<int, int> f = PQ.top(); PQ.pop();
        int u = f.second;
        color[u] = 2;
        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] == 2) 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] = 1;
            } 
        } 
    } 

    return;
}


int main()
{
    //freopen("in3.txt","r",stdin);
    int u,k,v,c;
    cin>>n;
    for (int i = 0; i < n; i++)
    {
        cin>>u>>k;
        for (int j = 0; j < n; j++)
        {
            cin>>v>>c;
            adj[u].push_back(make_pair(v,c));
        } 
    } 
    dijkstra();
    for (int i = 0; i < n; i++)
    {
        cout<<i<<" "<<d[i]<<endl; 
    } 
    return 0;
}

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

static const int MAX=1000;
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 color[MAX];
  int d[MAX];

  for(int i=0;i<n;i++){
    d[i]=INT_MAX;
    color[i]=WHITE;
  }

  d[0]=0;
  PQ.push(make_pair(0,0));
  color[0]=GRAY;

  while(!PQ.empty()){
    int u;
    pair<int,int> f=PQ.top();
    PQ.pop();
    u=f.second;

    color[u]=BLACK;

    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;
	PQ.push(make_pair(d[v]*(-1),v));
	color[v]=GRAY;
      }
    }
  }

  for(int i=0;i<n;i++) cout<<i<<" "<<d[i]<<endl;

}

int main(){
  int k,u,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;
}