Go: package main

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

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

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 =1200;
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<bits/stdc++.h>
using namespace std;

shortcost[10000][10000];//cost[a][b] a??????b????§?????????????????????????
long long int d[10000];//??????s?????????????°??????¢
bool used[10000];
int arrow;//????????°

const int INF = 10000000;

void dijkstra(){
  fill(d,d+arrow,INF);
  fill(used,used + arrow,false);
  d[0] = 0;

  while(1){
    int v=-1;
    // ???????????????????????????????????????????????¢???????°???????????????¢???
    for(int u=0;u<arrow;u++){
      if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
    }

    if(v == -1) break;

    used[v] = true;

    for(int u=0; u<arrow; u++){
      if(cost[v][u] != INF){
        d[u] = min(d[u],d[v] + cost[v][u]);
      }
    }
  }

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

}

int main(){

    cin >> arrow;

    int n,a,v,c;



    for(int i=0;i<arrow;i++){
      for(int j=0;j<arrow;j++){
        cost[i][j] = INF;
      }
    }

    for(int u=0;u<arrow;u++){

      cin >> n >> a;

      for(int i=0; i<a;i++){
        cin >> v >> c;
        cost[n][v] = c;
      }
    }

    dijkstra();

    return 0;
}

C++: #include<cstdio>
#include<queue>
#include<vector>
#include<iostream>
using namespace std;
int d[10005], visited[10005];
vector<pair<int, int>> G[10005];
int n, INFTY = (1<<30);
priority_queue<pair<int, int>> Q;
void dijkstra()
{
  for(int i=0; i<n; i++)
  {
    d[i] = INFTY; visited[i] = 0;
  }
  d[0] = 0;
  Q.push(make_pair(0, 0));
  while(!Q.empty())
  {
    int c = Q.top().first;
    int v = Q.top().second;
    Q.pop();
    //if(d[v] < -c) break;
    visited[v] = 1;
    for(int i=0; i<G[v].size(); i++)
    {
      pair<int, int> p = G[v][i];
      int u = p.second, cost = p.first;
      if(visited[u]==0 && d[u] > cost + d[v])
      {
        d[u] = cost + d[v];
        Q.push(make_pair(-d[u], u));
      }
    }
  }
  for(int i=0; i<n; i++)
  {
    printf("%d %d\n", i, d[i]);
  }
}
int main()
{
  scanf("%d", &n);
  int u, v, c, k;
  for(int i=0; i<n; i++)
  {
    scanf("%d%d", &u, &k);
    for(int j=0; j<k; j++)
    {
      scanf("%d%d", &v, &c);
      G[u].push_back(make_pair(c, v));
    }
  }
  dijkstra();
  return 0;
}

C++: #include <iostream>
#include <queue>
#include <vector>
#include <utility>
using namespace std;
typedef pair<int, int> P;
struct edge {int to, cost;};
const int INF = 2100000000;
int n;
vector<edge> G[10010];


vector<int> dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, s));
    vector<int> d(n, INF);
    d[s] = 0;
    while (!que.empty()) {
        P p = que.top(); que.pop();
        int v = p.second;
        if (d[v] < p.first) continue;
        for (auto e: G[v]) {
            if (d[e.to] > d[v] + e.cost) {
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to], e.to));
            }
        }
    }
    return d;
}

int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k, v, c;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[u].push_back(edge {v, c});
        }
    }
    vector<int> d = dijkstra(0);
    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }

    return 0;
}

C++: #include<iostream>
#include<vector>
#include<queue>
#define INF 2e9
using namespace std;

void Dikstra(const vector<vector<pair<int, int> > >& G, vector<int>& d){
    d[0] = 0;
    priority_queue<pair<int, int> , vector<pair<int, int> >, greater<pair<int, int> > > PQ;
    PQ.push(make_pair(0, 0));
    vector<bool> is_black(d.size(), false);
    is_black[0] = true;
    while (!PQ.empty()) {
        int t = PQ.top().second;
        PQ.pop();
        is_black[t] = true;
        for (int i = 0; i < G[t].size(); i++) {
            int v = G[t][i].first;
            int w = G[t][i].second;
            if (!is_black[v] && d[t] + w < d[v]) {
                d[v] = d[t] + w;
                PQ.push(make_pair(d[v], v));
            }
        }
    }

}

int main(){
    int n;
    cin >> n;
    vector<vector<pair<int, int> > > G(n);
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v, c;
            cin >> v >> c;
            G[u].push_back(make_pair(v, c));
        }
    }
    vector<int> d(n, INF);
    Dikstra(G, d);
    for (int i = 0; i < n; i++) {
       cout << i << " " << d[i] << endl;
    }

    return 0;
}