Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
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 = i
	pq[j].index = j
}
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
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
using namespace std;
const int maxn=1000000;
const int infly=(1<<21);
const int white=0;
const int grey=1;
const int black=-1;

struct node{
    int k;
    int to;
    int next;
};

struct node m[2*maxn+5];
int head[maxn+5],n=0;
int color[maxn+5],d[maxn+5],p[maxn+5];
int tu,k,v,c,nn;
int cnt=0;

void add(int u,int v,int tot)
{
    m[++n].k=v;
    m[n].next=head[u];
    m[n].to=tot;
    head[u]=n;
}

void ds()
{
    priority_queue<pair<int, int> > p;
    for(int i=0;i<=maxn;i++)
    {
        color[i]=white;
        d[i]=infly;
    }

    d[0]=0;
    p.push(make_pair(0,0));
    color[0]=grey;

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

        color[u]=black;

        for(int j=head[u];j;j=m[j].next)
        {
            int v=m[j].k;
            if(color[v]==black) continue;
            if(d[v]>d[u]+m[j].to)
            {
                d[v]=d[u]+m[j].to;
                p.push(make_pair(d[v]*(-1),v));
                color[v]=grey;
            }
        }
    }
}

int main()
{
    scanf("%d",&nn);
    for(int i=1;i<=nn;i++)
    {
        scanf("%d%d",&tu,&k);
        for(int j=1;j<=k;j++)
        {
            scanf("%d%d",&v,&c);
            add(tu,v,c);
        }
    }


    ds();
    for(int i=0;i<nn;i++)
    {
        printf("%d ",i);
        if(d[i]!=infly) printf("%d\n",d[i]);
        else printf("-1\n");
    }

    return 0;
}

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

typedef struct{
  int A[10010];
  long long ans;
}node;
node T[10010];
int Q[100300003];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    num=Q[head++];
        if(head==100300002)head=1;
    for(int i=0;i<n;i++){
      if(T[num].A[i]!=-1){
	if(T[i].ans>T[num].ans+T[num].A[i]){
	  T[i].ans=T[num].ans+T[num].A[i];
	  Q[tail++]=i;
	  	  if(tail==100300002)tail=1;
	}
      }
    }
  }
}

int main(){
  int num,son,z,w;
  cin>>n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      T[i].A[j]=-1;
    }
  }


  for(int i=0;i<n;i++){
    cin>>num>>son;
    T[num].ans=LONG_LONG_MAX;
    for(int j=0;j<son;j++){
      cin>>z>>w;
      T[num].A[z]=w;
      }
  }
  Q[0]=0;
  T[0].ans=0;
  function(0);
 
  for(int i=0;i<n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }
  return 0;
}

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

void solve(){
  int n; cin >> n;
  vector<vector<pair<int, int> > > v(n);
  for(int i = 0; i < n; i++){
    int u, k; cin >> u >> k;
    for(int j = 0; j < k; j++){
      int a, b; cin >> a >> b;
      v[u].push_back(make_pair(a, b));
    }
  }
  int d[n];
  bool c[n];
  for(int i = 0; i < n; i++){
    c[i] = 0;
    d[i] = 10000000;
  }
  priority_queue<pair<int, int > > pq;
  pq.push(make_pair(0, 0));
  d[0] = 0;
  while(pq.empty() == false){
    int x = pq.top().second;
    pq.pop();
    c[x] = 1;
    for(int i = 0; i < v[x].size(); i++){
      int y = v[x][i].first;
      if(c[y] == 0){
        if(d[y] > d[x] + v[x][i].second){
          d[y] = d[x] + v[x][i].second;
          pq.push(make_pair(d[y] * (-1), y));
        }
      }
    }
  }
  for(int i = 0; i < n; i++){
    cout << i << " " << d[i] << endl;
  }
  return;
}

int main(){
  solve();
  return 0;
}

C++: #include<stdio.h>
int v[10001][10001];
int a[10001][10001];
int d[10001];
int pi[10001];
char color[10001];
int n,mincost;
int k[10001];

void dijkstra(void);

int main(){
  int i,j,u;

  scanf("%d",&n);
  for(i=0;i<n;i++){
    for(j=0;j<n;j++){
      a[i][j]=0;
    }
  }

  for(i=0;i<n;i++){
    scanf("%d %d" ,&u,&k[i]);      
  for(j=1;j<=k[i];j++){
     scanf("%d",&v[u][j]);
     scanf("%d",&a[u][v[u][j]]);   
    }
  }
  dijkstra();

  for(i=0;i<n;i++){
    printf("%d %d\n",i,d[i]);
  }

  return 0;
}

void dijkstra(void){
  int i,j,u,min;
  
  for(i=0;i<n;i++){
    d[i]=2000000000;
    pi[i] = -1;
    color[i]='W';
  }
  d[0]=0;
  while(1){
    mincost = 2000000000;
    for(i=0;i<n;i++){
      if(color[i]!='B' && d[i] < mincost){
	mincost = d[i];
        u = i;
      }
    }
    if(mincost==2000000000) break;
    color[u]='B';
  
  for(i=0;i<n;i++){
    if(color[i]!='B' && a[u][i]!=0  && d[u]+a[u][i]<d[i]){
      pi[i] = u;
      d[i]=d[u]+a[u][i];
     }
   }
  }
}