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

	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 <queue>
#include <utility>
#include <vector>
using namespace std;

const int MAX_N = 100;
const int INF = (1 << 21);

int N;
vector<pair<int, int> > A[MAX_N];

void dj() {
  int d[MAX_N], c[MAX_N];

  // (first: distance*-1, second: adjacent)
  priority_queue<pair<int, int> > PQ; 

  for (int i = 0; i < N; i++) {
    d[i] = INF;
    c[i] = -1;
  }

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

  while (!PQ.empty()) {
    pair<int, int> t = PQ.top(); PQ.pop();
    int cur_n = t.second;
    c[cur_n] = 1;

    if (d[cur_n] < t.first * -1) continue;

    for (int i = 0; i < A[cur_n].size(); i++) {
      int adj_n = A[cur_n][i].first;

      if (c[adj_n] == 1) continue;

      if (d[cur_n] + A[cur_n][i].second < d[adj_n]) {
        d[adj_n] = d[cur_n] + A[cur_n][i].second;
        PQ.push(make_pair(d[adj_n] * -1, adj_n));
        c[adj_n] = 0;
      }
    }
  }

  for (int i = 0; i < N; i++)
    cout << i << ' ' << d[i] << endl;
}

int main() {
  cin >> N;

  for (int i = 0; i < N; i++) {
    int cur_n, k; cin >> cur_n >> k;

    for (int j = 0; j < k; j++) {
      int u, v; cin >> u >> v;
      A[cur_n].push_back(make_pair(u, v));
    }
  }

  dj();

  return 0;
}

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

static const int N = 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[N];

void dijkstra(int s) {
	int color[N], d[N];
	for (int i = 0; i < n; i++) {
		color[i] = white;
		d[i] = inf;
	}
	priority_queue<pair<int, int> > PQ;
	d[s] = 0;
	color[s] = gray;
	PQ.push(make_pair(s, 0));
	while (!PQ.empty()) {
		pair <int, int> f = PQ.top();
		PQ.pop();
		int u = f.second;
		color[u] = black;
		for (int k = 0; k < adj[u].size(); k++) {
			int v = adj[u][k].first;
			if (color[v] == black)
				continue;
			if (d[v] > d[u] + adj[u][k].second) {
				d[v] = d[u] + adj[u][k].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 << '\n';
		} else {
			cout << i << " " << d[i] << '\n';
		}
	}
}
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;
}

C++: #include <bits/stdc++.h>
 
using namespace std;
 
#define FOR(i,s,e) for((i)=(s);(i)<(int)(e);(i)++)
#define REP(i,e) FOR(i,0,e)
 
#define all(o) (o).begin(), (o).end()
#define psb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
 
typedef long long ll;
typedef pair<int, int> PII;
 
const double EPS = 1e-10;
 
typedef struct edge_def {
  int from;
  int to;
  int cost;
 
  edge_def(int _from, int _to, int _cost) {
    from = _from;
    to   = _to;
    cost = _cost;
  }
} edge;
 
const int INF = INT_MAX;
const int V = 10000;
int n, t;
vector<edge> es[V];
int d[V];
 
void dijkstra(int s) {
  int i;
  priority_queue<PII, vector<PII>, greater<PII > > q;
  for (i=0; i<n; i++) d[i] = INF;
  d[s] = 0;
  q.push(PII(0, s));
 
  while (q.size()) {
    PII p = q.top();
    q.pop();
    int v = p.second;
 
    if (d[v] < p.first) continue;
 
    for (i=0; i<(int)es[v].size(); i++) {
      edge e = es[v][i];
      if (d[e.to] > d[v] + e.cost) {
        d[e.to] = d[v] + e.cost; 
        q.push(PII(d[e.to], e.to));
      }
    }
  }
}
 
int main() {
  int i, j, k;
  int u, v, c;
  for (i=0; i<V; i++) es[i].clear();
 
  scanf("%d ", &n);
  for (i=0; i<n; i++) {
    scanf("%d%d ", &u, &k);
    for (j=0; j<k; j++) {
      scanf("%d%d ", &v, &c);
      es[u].psb(edge(u, v, c));
    }
  }
 
  dijkstra(0);
 
  for (i=0; i<n; i++) {
    printf("%d %d\n", i, d[i]);
  }
 
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#define INFTY 2000000001
#define LEN 1000000
using namespace std;
struct edge {
  int from,to,cost,k;
};
edge es[LEN];
int main(){
  int n,u,k,E,c,v;
  int d[LEN];
  E = 0;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    for(int j=0;j<k;j++){
      cin>>v>>c;
      es[E].from = u;
      es[E].to = v;
      es[E++].cost = c;
    }
  }
  for(int i=0;i<n;i++)d[i] = INFTY;
  d[0] = 0;
  while(true){
    bool update = false;
    for(int i=0;i<E;i++){
      edge e = es[i];
      if(d[e.from] != INFTY && d[e.to] > d[e.from] + e.cost){
    d[e.to] = d[e.from] + e.cost;
    update = true;
      }
    }
    if(update==false)break;
  }
  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;
}