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<climits>
#include<cstring>
#define INF INT_MAX
using namespace std;
typedef unsigned long long ull;
int n;
int A[1000][1000];
ull D[1000][1000];
 
void Init(int f){
  for(int i=0;i<=f+50;i++){
    for(int j=0;j<=f+50;j++)D[i][j] = INF;
  }
 
}
 
int main(){
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
  
  for(int i=0;i<n;i++){
    scanf("%d %d",&u,&k);    
    for(int j=0;j<k;j++){
      scanf("%d %d",&V,&C);
      D[u][V] = C;
      D[V][u] = C;
    }    
  }
  
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++){
    cout << i << " " << D[0][i] << endl;
  }
 
  return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		d[i] = INF;
		used[i] = false;
	}
	d[s] = 0;
	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] && ((v == -1) || d[u] < d[v])) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}
}

int main() {
	for (int i = 0; i < V+100; i++) {
		for (int j = 0; j < V+100; j++) {
			cost[i][j] = INF;//iからjへの辺の重さ
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);

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

C++: #include <iostream>
#define INF 2000000
#define MAX 100
#define WHITE 0
#define BLACK 1

using namespace std;

int n, d[MAX], color[MAX], w[MAX][MAX];

void dijkstra(int s){
    int u;
    for(u = 0; u < n; u++){
        d[u] = INF;
        color[u] = WHITE;
    }
    d[s] = 0;

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

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

int main(){
    int i, j;
    cin >> n;
    for(i = 0; i < n; i++){
        for(j = 0; j < n; j++){
            w[i][j] = INF;
        }
    }

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

    dijkstra(0);

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

    return 0;
}

C++: #include<iostream>
#include<algorithm>
#define MAX 120
#define WHITE -1
#define GRAY 0
#define BLACK 1
#define INFTY (1 << 21)

using namespace std;

int n;
int M[MAX][MAX];
int color[MAX], d[MAX], p[MAX];

void dijkstra(){
    
    int mini;
    
    for(int i=0; i<n; i++){
        color[i] = WHITE;
        d[i] = INFTY;
    }
    
    d[0] = 0;
    color[0] = GRAY;
    
    while(1){
        mini = INFTY;
        int u = -1;
        
        for(int i=0; i<n; i++){
            if(mini > d[i] && color[i] != BLACK){
                u=i;
                mini = d[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[v] > d[u] + M[u][v]){
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                }
            }
        }
    }
    
    
    for(int i=0; i<n; i++){
        if(d[i] != INFTY){
            cout << i << " " << d[i] << endl;
        }
        
        //cout << i << " " << d[i] << endl;
    }
    
}


int main(){
    cin >> n;
    
    int k, c, u, v;
    
    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();
    
    return 0;
}

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

#define go first
#define ct second

int cost[100 + 10] , cost_ps[100 + 10];
int n,vf,k,v,c;

int v_k[100];

vector< pair<int, int> > went[100];

pair<int, int> p_tmp;

int  check_go(int st)
{
	int i;
	int ret=0;

	for (i = 0; i < v_k[st]; i++)
	{
		if (cost_ps[went[st][i].go] > cost[st] + went[st][i].ct || cost_ps[went[st][i].go] == -1)
		{
			cost_ps[went[st][i].go] = cost[st] + went[st][i].ct;
		}
	}

	for (i = 1; i < n; i++)
	{
		if (cost_ps[ret] > cost_ps[i] && cost[i]==-1 && cost_ps[i]!=-1 || cost[ret] != -1 )
		{
			ret = i;
			//printf("ret=%d\n", ret);
		}
	}

	cost[ret] = cost_ps[ret];
	//cout << "A" << cost[ret] << endl;

	return ret;

}

int main()
{
	int i,j;
	int st_num=0;

	cin >> n;

	for (i = 0; i < n; i++)
	{
		cost[i] = cost_ps[i] = -1;

		cin >> vf ;
		cin >> v_k[vf];
		for (j = 0; j < v_k[vf] ; j++)
		{
			cin >> p_tmp.go >> p_tmp.ct;

			went[vf].push_back(p_tmp);
		}
	}

	cost[0] = cost_ps[0] = 0;

	for (i = 1; i < n; i++)
	{
		st_num = check_go(st_num);
	}

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

	return 0;
}