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)
	}
}

Python: import heapq

n = int(input())
d = [float("inf") for i in range(n)]
d[0] = 0
g = []
q = []

for i in range(n):
    heapq.heappush(q, (d[i], i))
    inp = list(map(int, input().split()))
    tmp = []
    for j in range(inp[1]):
        tmp.append(inp[2*j+2:2*j+4])
    g.append(tmp)

while q:
    q_pop = heapq.heappop(q)
    i = q_pop[1]
    if q_pop[0] > 100000*100000:
        continue
    for node in g[i]:
        d_tmp = d[i] + node[1]
        if d_tmp < d[node[0]]:
            d[node[0]] = d_tmp
            heapq.heappush(q, (d_tmp, node[0]))

for i in range(n):
    print(i, d[i])

Python: n=int(input())
inf=10**15;d=[inf]*n;d[0]=0
node=[[]for _ in range(n)]
for i in range(n):
	x=list(map(int,input().split()))
	for j in range(x[1]):
		node[i].append((x[j*2+2],x[j*2+3]))
from heapq import heappush,heappop
pq=[]
visited=[False]*n
heappush(pq,(0,0))#dis,num
while pq:
	u=heappop(pq)#1回あたりO(log|V|)がO(|V|)回ある
	u_dis=u[0];u_num=u[1]
	visited[u_num]=True
	for x in node[u_num]:
		x_dis=x[1];x_num=x[0]
		if visited[x_num]==False:
			if d[u_num]+x_dis<d[x_num]:
				d[x_num]=d[u_num]+x_dis
				heappush(pq,(d[x_num],x_num))
				#1回あたりO(log|V|)がO(|E|)回ある
for i in range(n):
	print(i,d[i])

Python: # -*- coding: utf-8 -*-
"""
http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_12_C

???????§????????????????II
"""
from enum import Enum
from heapq import heappush, heappop, heapify
import itertools


class Priority_queue():
    # https://docs.python.jp/3/library/heapq.html
    def __init__(self):
        self.pq = []                         # list of entries arranged in a heap
        self.entry_finder = {}               # mapping of tasks to entries
        self.REMOVED = '<removed-task>'      # placeholder for a removed task
        self.counter = itertools.count()     # unique sequence count

    def add_task(self, task, priority=0):
        'Add a new task or update the priority of an existing task'
        if task in self.entry_finder:
            self.remove_task(task)
        count = next(self.counter)
        entry = [priority, count, task]
        self.entry_finder[task] = entry
        heappush(self.pq, entry)

    def remove_task(self, task):
        'Mark an existing task as REMOVED.  Raise KeyError if not found.'
        entry = self.entry_finder.pop(task)
        entry[-1] = self.REMOVED

    def pop_task(self):
        'Remove and return the lowest priority task. Raise KeyError if empty.'
        while self.pq:
            priority, count, task = heappop(self.pq)
            if task is not self.REMOVED:
                del self.entry_finder[task]
                return task
        raise KeyError('pop from an empty priority queue')

    def top_task(self):
        return self.pq[0][-1]

    def get_length(self):
        return len(self.pq)

    def is_empty(self):
        return self.get_length()==0


class Sssp(object):
    """ single source shortest path """
    INFINITY = 999999999
    class Status(Enum):
        """ ?????????????¨??????¶??? """
        white = 1  # ????¨????
        gray = 2  # ?¨???????
        black = 3  #?¨???????

    def __init__(self, data):
        num_of_nodes = len(data)
        self.color = [Sssp.Status.white] * num_of_nodes  # ????????????????¨??????¶???
        self.d = [Sssp.INFINITY] * num_of_nodes  # ?§???????????????????
        self.p = [-1] * num_of_nodes  # ????????????????????????????¨?????????????????????????
        self.adj = [[] for _ in range(num_of_nodes)]
        self.make_adj(data)


    def make_adj(self, data):
        # ??£??\??????????????????
        for d in data:
            my_id = d[0]
            d = d[2:]
            while len(d) > 1:
                to_node, cost = d[0], d[1]
                self.adj[my_id].insert(0, (to_node, cost))
                d = d[2:]


    def dijkstra(self, start):
        self.d[start] = 0
        pq = Priority_queue()
        pq.add_task((0, 0), 0)

        while not pq.is_empty():
            cost, u = pq.pop_task()
            self.color[u] = Sssp.Status.black
            if self.d[u] < cost:
                continue

            for n, cost in self.adj[u]:
                if n is None:
                    break
                v = n
                if self.color[v] == Sssp.Status.black:
                    continue
                if self.d[v] > self.d[u] + cost:
                    self.d[v] = self.d[u] + cost
                    pq.add_task((self.d[v], v), cost)
                    self.color[v] = Sssp.Status.gray


if __name__ == '__main__':
    # ??????????????\???
    num = int(input())
    data = []
    for i in range(num):
        data.append(list(map(int, input().split(' '))))

    # ???????????¢?´¢
    s = Sssp(data)
    s.dijkstra(0)

    # ???????????¨???
    for i in range(num):
        print('{0} {1}'.format(i, s.d[i]))

Python: import sys
from heapq import*
def m():
 n=int(input())
 A=[]
 for e in sys.stdin:
  e=list(map(int,e.split()))
  A+=[zip(e[2::2],e[3::2])]
 d=[0]+[float('inf')]*n
 H=[(0,0)]
 while H:
  u=heappop(H)[1]
  for v,c in A[u]:
   t=d[u]+c
   if d[v]>t:
    d[v]=t
    heappush(H,(t,v))
 print('\n'.join(f'{i} {d[i]}'for i in range(n)))
m()