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 <algorithm>
#include <queue>
using namespace std;

int n;
vector <pair<int, int> > adj[10000];

//dijkstra
void dijkstra() {
  priority_queue<pair<int, int> > PQ;
  int d[10000];
  for ( int i = 0; i < n; i++ ) {
    d[i] = 10000000;
  }
  d[0] = 0;
  PQ.push(make_pair(0,0));

  while ( !PQ.empty() ) {
    pair<int, int> f = PQ.top(); PQ.pop();
    int u = f.second;
    if ( d[u] < f.first * -1 ) continue;

    for ( int j = 0; j < adj[u].size(); j++ ) {
      int v = adj[u][j].first;
      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));
      }
    }
  }

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

int main() {
  int k,u,v,c;
  
  //入力
  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;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
const int MAX_N =10000;
int V;
int cost[MAX_N][MAX_N];
int d[MAX_N];
bool visit[MAX_N];
void dijkstra(int s){
	d[s]=0;
	while(true){
		int v =-1;
		for(int u = 0;u < V;u++){
			if(!visit[u]&&(v==-1||d[u] < d[v])){
				v = u;
			}
		}
		if(v==-1)break;
		visit[v]=true;
		for(int u = 0;u < V;u++){
			d[u] =min(d[u],d[v]+cost[v][u]);
		}
	}
}

int main(){
	cin>>V;
	for(int i =0;i <V;i++){
		d[i]=INF;
		visit[i]=false;
		for(int j =0;j <V;j++){
			cost[i][j]=INF;

		}
	}
	for(int i =0;i < V;i++){
		int u,k;
		cin>>u>>k;
		for(int j =0;j <k;j++){
			int v,c;
			cin>>v>>c;
			cost[u][v]=c;
		}
	}
	dijkstra(0);
	for(int i =0;i <V;i++){
		cout <<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: #include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define ld long double
#define INF 1000000000000000000
typedef pair<ll, ll> pll;
typedef pair<int, int> pint;

struct edge {
    ll to;
    ll cost;
};

int N;
vector<vector<edge>> G;
vector<ll> d(150);

void dijkstra() {
    priority_queue<pll, vector<pll>, greater<pll>> que;
    que.push({0, 0});
    d.assign(N, INF);
    d[0] = 0;
    while (!que.empty()) {
        pll 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({d[e.to], e.to});
            }
        }
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> N;
    G.resize(N);
    rep(i, N) {
        ll a, b;
        cin >> a >> b;
        rep(j, b) {
            ll c, d;
            cin >> c >> d;
            G[a].push_back({c, d});
        }
    }

    dijkstra();
    rep(i, N) { cout << i << " " << d[i] << endl; }
}

C++: #include<bits/stdc++.h>
using namespace std;
#define MOD 1000000007
#define INF (1<<20)
#define white 0
#define gray 1
#define black 2

int n;
vector<pair<int,int> > W[10000]; 
int color[10000],d[10000],p[100];

void dijkstra(int s) {
  d[s] = 0;
  priority_queue<pair<int,int> > PQ;
  PQ.push(make_pair(0,s));

  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 i = 0;i < W[u].size();i++) {
      int v = W[u][i].first;
      if(color[v] == black) continue;
      if(d[v] > d[u] + W[u][i].second) {
        d[v] = d[u] + W[u][i].second;
        PQ.push(make_pair(d[v] * (-1),v));
      }
    }
  }

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

int main() {

  cin >> n;
  

  for(int i = 0;i < n;i++) {
    int u,k;
    cin >> u >> k;
    color[i] = white;
    d[i] = INF;
    for(int j = 0;j < k;j++) {
      int v,c;
      cin >> v >> c;
      W[u].push_back(make_pair(v,c));
    }
  }

  dijkstra(0);

}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#define INF 1<<20
using namespace std;
int n;
int A[1000][1000];
int d[1000];
bool used[1000];
int D[1000][1000];
 
void Init(int f){
  for(int i=0;i<f;i++){
    for(int j=0;j<f;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++){
    printf("%d %d\n",i,D[0][i]);
  }
 
  return 0;
}