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 <bits/stdc++.h>

using namespace std;

vector<int> adja[10000], cost[10000];

#define INF (1 << 30)

int main() {
	int n, id, k;

	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> id >> k;
		adja[id].resize(k);
		cost[id].resize(k);
		for (int j = 0; j < k; ++j) {
			cin >> adja[id][j] >> cost[id][j];
		}
	}

	priority_queue<pair<int, int>> que;
	que.push(make_pair(0, 0)); //cost, node
	int best[10000];
	fill(best, best + n, INF);
	best[0] = 0;

	while (!que.empty()) {
		pair<int, int> top = que.top();
		que.pop();

		for (int j = 0, len = adja[top.second].size(); j < len; ++j) {
			if (best[adja[top.second][j]] > top.first + cost[top.second][j]) {
				best[adja[top.second][j]] = top.first + cost[top.second][j];
				que.push(make_pair(top.first + cost[top.second][j], adja[top.second][j]));
			}
		}
	}

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

	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
#define inf 200000000
#define Max 10000
#define W 0
#define G 1
#define B 2
using namespace std;
vector<pair<int,int>> g[Max];
int n,d[Max];
void dikstr(int s){
	int color[Max];
int i,j;
	pair<int,int> u;
	priority_queue<pair<int,int>> PQ;
	for(i=0;i<n;i++){
	color[i]=W;
		d[i]=inf;
	}
	d[s]=0;
	PQ.push(make_pair(s,0));
	color[s]=G;
	while(!PQ.empty()){
		u=PQ.top();PQ.pop();
		int uf=u.first,us=u.second;
		color[us]=B;
		if(d[us]<uf*(-1))
		continue;
		
		for( j=0;j<g[us].size();j++){
			int v=g[us][j].first;
			if(color[v]!=B){
				if(d[us]+(g[us][j].second)<d[v]){
					d[v]=d[us]+(g[us][j].second);
					color[v]=G;
					PQ.push(make_pair(d[v]*(-1),v));
				}
			}
		}
	}
	
	
}

main(){
	int u,k,v,c;
	scanf("%d",&n);
	int i,j;
	for(i=0;i<n;i++){
		scanf("%d%d",&u,&k);
		for(j=0;j<k;j++){
			scanf("%d%d",&v,&c);
			g[u].push_back(make_pair(v,c));
		}
	}
	dikstr(0);
	for(i=0;i<n;i++){
		printf("%d %d\n",i,d[i]);
	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <vector>

using namespace std;

const int MAX=10000;
const int INFTY=(1<<21);
const int WHITE=0;
const int GRAY=1;
const int BLACK=2;

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

void dijkstra(){
    priority_queue<pair<int, int> > PQ;
    int color[MAX],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;
    }

    return;
}

int main()
{
    cin>>n;
    int k,u,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();

}

C++: #include <stdio.h>

int a,b, c,n,u,w[10000][10000],color[10000],d[10000];

int main(){
  int i,j,mincost,sum=0;
  scanf("%d",&n);
 for(i=0;i<n;i++)
   for(j=0;j<n;j++)w[i][j]=100008;

  for(i=0;i<n;i++){
    scanf("%d%d",&a,&c);
      for(j=0;j<c;j++){
scanf("%d",&b);
 scanf("%d",&w[a][b]);    
}
    }
 
  for(i=0;i<n;i++){
    d[i] =100008;
    color[i] =0;
  }
  d[0]=0;

  while (1){
    mincost=100008;    
for(i=0;i<n;i++){
      if (color[i] != 1 && d[i] < mincost){
	mincost = d[i];
	u = i;
      }
    }
    if (mincost ==100008)
      break;
    color[u] = 1;
    for (i=0;i<n;i++){
      if (color[i] != 1 && d[u]+w[u][i] < d[i]){
	d[i] = d[u]+w[u][i];
      }
    }
  }
 
 for (i=0;i<n;i++)
 printf("%d %d\n",i,d[i]); 

  return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF (1 << 21)
typedef long long ll;

int main() {
  int n;
  cin >> n;

  vector<int> V[n];
  int E[n][n];
  int d[n];
  int visited[n];

  REP(x, n) {
    REP(y, n) {
      E[x][y] = INF;
    }
    d[x] = INF;
    visited[x] = 0;
  }

  REP(_, n) {
    int u, k;
    cin >> u >> k;
    REP(__, k) {
      int v, c;
      cin >> v >> c;
      V[u].push_back(v);
      E[u][v] = c;
      // E[v][u] = c;
    }
  }

  d[0] = 0;
  REP(_, n) {
    int minv = -1;
    int mincost = INF;
    REP(v, n) {
      if (!visited[v] && d[v] < mincost) {
        minv = v;
        mincost = d[v];
      }
    }
    visited[minv] = 1;
    for (vector<int>::iterator it = V[minv].begin(); it != V[minv].end(); it++) {
      if (E[minv][*it] < INF && d[minv] + E[minv][*it] < d[*it]) {
        d[*it] = d[minv] + E[minv][*it];
      }
    }
  }

  REP(i, n) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}