Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	route := make([][]Node, n)
	weight := make([]int, n)
	for i := 0; i < n; i++ {
		weight[i] = NIL
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		route[i] = make([]Node, k)
		for j := 0; j < k; j++ {
			route[u][j] = Node{id: scanInt(), weight: scanInt()}
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for _, nextNode := range route[node.id] {
			if weight[nextNode.id] != NIL {
				continue
			}
			nextNode.weight += node.weight
			heap.Push(h, nextNode)
		}
	}

	for i, w := range weight {
		fmt.Println(i, w)
	}
}

C++: #include<bits/stdc++.h>
#define d first
#define wgt first
#define to second

using namespace std;

typedef pair<int,int> pii;
typedef vector<pii> vec;
typedef vector<vec> Graph;

Graph G(11000);
int n,d[11000];

void Dijkstra()
{
	bool used[1100];
	priority_queue<pii,vector<pii>,greater<pii> > pq;
	fill(d,d+n,INT_MAX);
	memset(used,false,sizeof(used));
	pq.push(make_pair(0,0));
	while(!pq.empty())
	{
		pii u=pq.top();pq.pop();
		if(used[u.to]) continue;
		used[u.to]=true;
		d[u.to]=u.d;
		for(int i=0;i<G[u.to].size();i++)
			if(d[G[u.to][i].to]>d[u.to]+G[u.to][i].wgt)
			{
				d[G[u.to][i].to]=d[u.to]+G[u.to][i].wgt;
				pq.push(make_pair(d[G[u.to][i].to],G[u.to][i].to));
			}
	}
}

int main()
{
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		int u,t;
		scanf("%d%d",&u,&t);
		for(int j=0;j<t;j++)
		{
			int v,w;
			scanf("%d%d",&v,&w);
			G[u].push_back(make_pair(w,v));
		}
	}
	Dijkstra();
	for(int i=0;i<n;i++)
		printf("%d %d\n",i,d[i]);
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define INF (1 << 30)

struct edge{

  int cost, to;

};

struct state{

  int node, cost;
  bool operator <(const state &b)const{
    return cost > b.cost;
  }
};

int n;
int d[10001];
vector<edge> glaph[10001];
priority_queue<state> qu;

void sss(){

  fill(d,d+10001,INF);
  qu.push((state){0,0});
  d[0] = 0;

  while(!qu.empty()){

    state info;
    info = qu.top();
    qu.pop();

    for(int i = 0; i < (double)glaph[info.node].size(); i++){
      if(d[glaph[info.node][i].to] > glaph[info.node][i].cost + d[info.node]){
      d[glaph[info.node][i].to] = glaph[info.node][i].cost + d[info.node];
      qu.push((state){glaph[info.node][i].to,d[info.node]}); 
      }
	}
  }

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



}

int main(){

  cin >> n;

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

  sss();


}

C++: #include <cstdio>
#include <queue>
#include <algorithm>

#define rep(i, n) for(int i = 0; i < (n); ++i)

using namespace std;

const int inf = 1e9;

typedef pair<int, int> P;

struct E{
	E(int t, int c): t(t), c(c){} 

	int t, c;
};

int n;
vector<E> g[10000];
int d[10000];

int main(){
	scanf("%d", &n);
	rep(i, n){
		int u, k;
		scanf("%d%d", &u, &k);
		rep(j, k){
			int v, c;
			scanf("%d%d", &v, &c);
			g[u].push_back(E(v, c));
		}
	}

	fill_n(d, n, inf);

	priority_queue<P, vector<P>, greater<P> > q;
	d[0] = 0;
	q.push(P(0, 0));
	while(!q.empty()){
		P v = q.top();
		q.pop();
		if(v.first > d[v.second]){
			continue;
		}
		rep(i, g[v.second].size()){
			E e = g[v.second][i];
			if(d[e.t] > v.first + e.c){
				d[e.t] = v.first + e.c;
				q.push(P(d[e.t], e.t));
			}
		}
	}

	rep(i, n){
		printf("%d %d\n", i, d[i]);
	}
	return 0;
}

C++: #include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <cstring>
#include <queue>
#include <vector>
#include <functional>
#include <map>
#include <set>
#include <cmath>
#include <string>
#define SIZE 10005
#define INF 10000005

using namespace std;
typedef long long int ll;
typedef pair <int,int> P;

int V;
ll K;

struct edge{int to,cost;};
vector<edge> G[SIZE];
int d[SIZE];

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()
{
	scanf("%d",&V);
	int u,k,v,c;
	for(int i=0;i<V;i++){
		scanf("%d%d",&u,&k);
		for(int j=0;j<k;j++){
			scanf("%d%d",&v,&c);
			G[u].push_back((edge){v,c});
		}
	}
	dijkstra(0);
	for(int i=0;i<V;i++){
		printf("%d %d\n",i,d[i]);
	}
	return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <cmath>
#include <ctype.h>
#include <string>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>
#include <list>
#include <cstring>
#include <stack>

using namespace std;

#define mod 1000000007

int main()
{
	int n;
	cin >> n;
	int ans[10001] = {};
	vector<vector<pair<int, int> > > graph(n + 1);
	for(int i = 0; i < n; i++){
		ans[i] = -1;
		int u, k;
		cin >> u >> k;
		for(int j = 0; j < k; j++){
			int v, c;
			cin >> v >> c;
			graph[u].push_back(make_pair(v, c));
		}
	}
	priority_queue<pair<int, int> > qu;
	qu.push(make_pair(0, 0));
	ans[0] = 0;
	while(!qu.empty()){
		int nowd = -(qu.top()).first;
		int nownode = (qu.top()).second;
		qu.pop();
		for(int i = 0; i < graph[nownode].size(); i++){
			int node = graph[nownode][i].first;
			int next = nowd + graph[nownode][i].second;
			if(ans[node] < 0 || ans[node] > next){
				ans[node] = next;
				qu.push(make_pair(-next, node));
			}
		}
	}
	for(int i = 0; i < n; i++){
		cout << i << " " << ans[i] << endl;
	}
}