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> 
using namespace std;
static const int INFTY = (1<<21);
int n, M[100][100];
int color[100],d[100],p[100];

void dijkstra()
{
    for (int i = 0; i < n; i++)
    {
        d[i] = INFTY;
        p[i] = -1;
        color[i] = 0;
    } 
    
    d[0] = 0;

    while (true)
    { 
        int mincost = INFTY;
        int u = -1;
        for (int i = 0; i < n; i++)
        {
            if (color[i] != 2 && d[i] < mincost )
            { 
                mincost = d[i];
                u = i;
            }         
        } 
        if (mincost == INFTY) break;
        color[u] = 2;
        for (int v = 0; v < n; v++)
        {
            if (color[v] != 2 && d[u] + M[u][v] < d[v])
            { 
                d[v] = d[u] + M[u][v];
                p[v] = u;
                color[v] = 1;
            }  
        } 
    } 

}

int main()
{
    //freopen("in3.txt","r",stdin);
    int u,k,v,c;
    cin>>n;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            M[i][j] = INFTY; 
        }  
    } 
    for (int i = 0; i < n; i++)
    {
        cin>>u>>k;
        for (int j = 0; j < k; j++)
        {
            cin>>v>>c; 
            M[u][v] = c; 
        } 
    } 
    
    dijkstra();

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

C++: #include <iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, M[MAX][MAX];

void dijkstra()
{
  int mincost;
  int d[MAX], color[MAX];

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

  d[0] = 0;
  color[0] = GRAY;
  while (true)
  {
    mincost = INFTY;
    int u = -1;
    for (int i = 0; i < n; i++)
    {
      if (color[i] != BLACK && d[i] < mincost)
      {
        mincost = d[i];
        u = i;
      }
    }

    if (u == -1)
    {
      break;
    }

    color[u] = BLACK;
    for (int v = 0; v < n; v++)
    {
      if (color[v] != BLACK && M[u][v] != INFTY)
      {
        if (d[u] + M[u][v] < d[v])
        {
          d[v] = d[u] + M[u][v];
          color[v] = GRAY;
        }
      }
    }
  }

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

int main()
{
  cin >> n;
  for (int i = 0; i < n; i++)
  {
    for (int j = 0; j < n; j++)
    {
      M[i][j] = INFTY;
    }
  }

  int k, c, u, v;
  for (int i = 0; i < n; i++)
  {
    cin >> u >> k;
    for (int j = 0; j < k; j++)
    {
      cin >> v >> c;
      M[u][v] = c;
    }
  }

  dijkstra();

  return 0;
}

C++: #include <bits/stdc++.h>

#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
#define INF 999999999

using namespace std;
typedef pair<int, int> P;
typedef pair<llong, llong> LP;
typedef pair<int, P> PP;
typedef pair<llong, LP> LPP;

struct edge { int to, cost; };
typedef pair<int, int> P;

int iy[]={0, 0, 1, -1};
int ix[]={1, -1, 0, 0};

int n, m, a, b;
vector<edge> G[101];
int d[101];

int main(){
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> i;
		cin >> m;
		for(int k=0;k<m;k++){
			cin >> a >> b;
			G[i].push_back({a,b});
		}
	}

	priority_queue<P, vector<P>, greater<P> > que;
	fill(d,d+n,INF);
	d[0] = 0;
	que.push(P(0,0));

	while(!que.empty()){
		P p = que.top(); que.pop();
		int u = p.second;
		if(d[u] < p.first) continue;
		for(int i=0;i<G[u].size();i++){
			edge e = G[u][i];
			if(d[e.to] > d[u]+e.cost){
				d[e.to] =d[u]+e.cost;
				que.push(P(d[e.to],e.to));
			}
		}
	}
	for(int i=0;i<n;i++){
		cout << i << " " << d[i] << endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
#include<string>
#include<cctype>
#include<cmath>
#include<queue>
#include<stack> 
#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
const int MAX_V=105;
int INF = 100000;
struct edge{int to,cost;};
typedef pair <int,int> P;

int V;
vector <edge> G[MAX_V];
int d[MAX_V];

void dijkstra(int s){
  priority_queue<P,vector<P>,greater<P> > que;
  fill(d,d+V,INF);
  d[s]=0;
  que.push(P(0,s));
  
  while(!que.empty()){
    P p = que.top(); que.pop();
    int v= p.second;
    if(d[v]<p.first)continue;
    for(int i=0 ;i<G[v].size();i++){
      edge e =G[v][i];
      if(d[e.to]>d[v]+e.cost){
        d[e.to] = d[v] + e.cost;
        que.push(P(d[e.to],e.to));
      }
    }
  }
} 
  
int main(){
  int n;
  cin >> n; V=n;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    rep(j,k){
      int to,cost;
      cin >> to >> cost;
      G[u].push_back(edge{to,cost});
    }
  }     

  dijkstra(0);
  rep(i,n){
    cout << i << ' ' << d[i] << endl;
  }
  return 0;
}