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>
#include <vector>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1<<21);

enum Color {
  WHITE, GRAY, BLACK
};

vector<pair<int, int> > adj[MAX];
int d[MAX];
Color color[MAX];
int n;

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

void dijkstra(int s) {
  init();
  d[s] = 0;
  priority_queue<pair<int, int> > PQ;
  PQ.push(make_pair(0, 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 j = 0; j < adj[u].size(); j++) {
      int v = adj[u][j].first;
      if (color[v] == BLACK) continue;
      if (d[u] + adj[u][j].second < d[v]) {
        d[v] = d[u] + adj[u][j].second;
        PQ.push(make_pair(d[v] * (-1), v));
        color[v] = GRAY;
      }
    }
  }
}


int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    int elem, index, v;
    cin >> v >> elem;
    for (int j = 0; j < elem; j++) {
      int u, cost;
      cin >> u >> cost;
      adj[v].push_back(make_pair(u, cost));
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; i++) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

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++: #define _CRT_SECURE_NO_WARNINGS

#include<iostream>
#include<functional>
#include<algorithm>
#include<stack>
#include<queue>
#include<iomanip>
#include<set>
#include<map>
#include<utility>
#include<string>
#include<vector>

using namespace std;

#define LL long long
const int dx[4] = { 1,-1,0,0 };
const int dy[4] = { 0,0,1,-1 };
bool OOA(int x, int y, int H, int W) { return (0 <= x && x<H) && (0 <= y && y<W); }

struct Edge{
	int fr,to,val;
	bool operator < (Edge x){
		return (val<x.val);
	}
};

struct Graph {
	struct Edge {
		int fr, to, val;
		Edge(int f, int t, int v) :fr(f), to(t), val(v) {}
	};

	int V, E, t;
	vector<int>cost;
	vector<bool>vzt;
	vector<vector<pair<int,int>>>adj;//to,val
	void init(int n,int dflt) {//dflt!=0
		t = 1;
		V = n;
		adj = vector<vector<pair<int,int>>>(V + 1);
		cost = vector<int>(V + 1, dflt);
		vzt = vector<bool>(V + 1, false);
		return;
	}

	void Dijkstra(int s){
		priority_queue<pair<int,int>>pq;
		pq.push({s,0});
		cost[s]=0;
		while(!pq.empty()){
			auto now=pq.top().first,ncos=pq.top().second;
			pq.pop();
			for(int i=0;i<adj[now].size();i++){
				if(cost[adj[now][i].first]>cost[now]+adj[now][i].second){
					cost[adj[now][i].first]=cost[now]+adj[now][i].second;
					pq.push({ adj[now][i].first,cost[adj[now][i].first] });
				}
			}
		}
		return;
	}
};

int n;
Graph G;

int main() {
	cin >> n;
	G.init(n,(1<<30));
	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.adj[u].push_back({v,c});
		}
	}
	G.Dijkstra(0);
	for(int i=0;i<n;i++){
		cout<<i<<" "<<G.cost[i]<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
#include<map>
#include<stack>
#include<queue>
using namespace std;
int inf = 1000000000;

class node{
public:
  int to;
  int from;
  int cost;
};

int main(void) {

  int n; scanf("%d", &n);
  vector<node> v;
  for(int i=0; i<n; i++){
    int u, k;
    scanf("%d %d", &u, &k);
    for(int j=0; j<k; j++){
      int vv, c;
      scanf("%d %d", &vv, &c);
      node t;
      t.from = u;
      t.to = vv;
      t.cost = c;
      v.push_back(t);
    }
  }

  vector<int> dist(n, inf);
  vector<bool> vis(n, false);

  priority_queue< pair<int, int> > pq;
  pq.push(make_pair(0, 0));
  dist[0] = 0;
  vis[0] = true;
  while( !pq.empty() ){
    pair<int, int> pos = pq.top();
    pq.pop();

    for(int i=0; i<v.size(); i++){
      if( pos.second != v[i].from ) continue;
      // if( vis[ v[i].to ] ) continue;
      if( dist[v[i].to] < dist[v[i].from] + v[i].cost ) continue;

      dist[v[i].to] = min(dist[v[i].to], dist[v[i].from] + v[i].cost);
      pq.push(make_pair(dist[v[i].to], v[i].to));
      vis[v[i].to] = true;
    }

  }

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

  return 0;
}

// EOF