Go: package main

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

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

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

// we want the ascending-priority-queue.
// So we use less than here.
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}

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

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 //for safety
	*pq = old[0 : n-1]
	return item
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist *[][]int, n int) *[]int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0
	heap.Init(&pq)

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range (*dist)[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return &shortests
}

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

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(&dist, n)
	for i, d := range *shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1 << 20);
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] = INFTY;
        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] == INFTY ? -1 : 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;
}

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

int x[10000][2000];
int x2[10000][2000];
int y[10000];
int z[10000];

int main() {
	memset(x, 1, sizeof(x));
	memset(y, 1, sizeof(y));
	int n, a, b, c, d, e;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a >> b;
		for (int i = 0; i < b; i++) {
			cin >> c >> d;
			x[a][z[a]] = c;
			x2[a][z[a]] = d;
			z[a]++;
		}
	}
	y[0] = 0;
	e = min(n, 1600);
	for (int i = 0; i < e; i++) {
		for (int j = 0; j < n; j++) {
			for (int k = 0; k < z[j]; k++) {
				y[x[j][k]] = min(y[x[j][k]], y[j] + x2[j][k]);
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << ' ' << y[i] << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define MAX 10000
#define INF INT_MAX
#define WHITE 0
#define GRAY 1
#define BLACK 2

vector<pair<int, int> > M[MAX];
int n;
int col[MAX];
int d[MAX];

void init() {
	for (int i = 0; i < n; i++) {
		col[i] = WHITE;
		d[i] = INF;
	}
}
void input() {
	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;
			M[u].push_back(make_pair(v, c));
		}
	}
}
void dijkstra(int s) {
	d[s] = 0;
	priority_queue<pair<int, int> > PQ;
	PQ.push(make_pair(d[s] * (-1), s));
	col[s] = GRAY;
	while (!PQ.empty()) {
		pair<int, int> f = PQ.top();
		PQ.pop();
		int u = f.second;
		col[u] = BLACK;
		if (d[u] < f.first * (-1))
			continue;
		for (int j = 0; j < M[u].size(); j++) {
			int v = M[u][j].first;
			if (col[v] != BLACK) {
				if (d[u] + M[u][j].second < d[v]) {
					d[v] = d[u] + M[u][j].second;
					col[v] = GRAY;
					PQ.push(make_pair(d[v] * (-1), v));
				}
			}
		}
	}
}
void output() {
	for (int i = 0; i < n; i++) {
		cout << i << " " << d[i] << endl;
	}
}

int main() {
	cin >> n;
	init();
	input();
	dijkstra(0);
	output();
	return 0;
}

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

int INF=1000000001;

typedef struct edge{
  int to;
  int cost;
}edge;

int N,E;
vector <edge> G[100001];
int mincost[100000];

void dikstra(){
  //priority_queue?????£?¨?
  typedef pair<int, int> P;
  priority_queue<P, vector<P>, greater<P> > Q;

  //mincost??????????????????????????????
  for(int i=0;i<N;i++){
    mincost[i]=INF;
  }
  mincost[0]=0;//??????????????°????????????0

  Q.push(P(0,0));
  //????????????????????????????????¬???
  while(!Q.empty()){
    int pos=Q.top().second;//position
    int pos_cost=Q.top().first;
    Q.pop();
    
    if(mincost[pos] < pos_cost ){
      continue;
    }

    for(int i=0;i<(int)G[pos].size();i++){
      edge e=G[pos][i];
      if(mincost[e.to]>pos_cost+e.cost){
        mincost[e.to]=pos_cost+e.cost;
        Q.push(P(mincost[e.to], e.to));
      }
    }
      
  }
  for(int i=0;i<N;i++){
      cout<<i<<' '<<mincost[i]<<endl;
    }
}

int main(){
  cin>>N;
  for(int i=0;i<N;i++){
    int id, k;
    cin >> id >> k;
    for(int j=0;j<k;j++){
      edge e;
      cin >> e.to >> e.cost;
      G[id].push_back(e);
    }
  }
  dikstra();
  return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repr(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define FORR(i, m, n) for (int i = (m); i >= (n); --i)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const ll mod2 = 998244353;
const int INF = 1000000005;
const int MAX = 10005;

vector<pair<int, int>> to[MAX];
bool seen[MAX];
int d[MAX], n;

void dijkstra(int u) {
  d[u] = 0;
  priority_queue<pair<int, int>> pq;
  pq.push(make_pair(0, 0));
  pair<int, int> p;
  while (!pq.empty()) {
    p = pq.top();
    pq.pop();
    seen[p.second] = true;

    for (pair<int, int> e: to[p.second]) {
      if (seen[e.second]) continue;
      if (d[p.second] + e.first < d[e.second]) {
        d[e.second] = d[p.second] + e.first;
        pq.push(make_pair(-d[e.second], e.second));
      }
    }
  }
}

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

  rep(i, n) {
    seen[i] = false;
    d[i] = INF;
  }

  dijkstra(0);

  rep(i, n) cout << i << " " << d[i] << endl;

  
  return 0;
}