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())
p=[-1 for i in range(n)]
inf=100000000
d=[inf for i in range(n)]
M=[[] for i in range(n)]
color=["white" for i in range(n)]
Q=[]
heapq.heapify(Q)

for i in range(n):
    tmp=list(map(int,input().split()))
    root=tmp[0]
    k=tmp[1]
    for j in range(k):
        M[root].append((tmp[2*(j+1)+1],tmp[2*(j+1)]))

def dijkstra(s):
    d[s]=0
    heapq.heappush(Q,(d[s],s))
    color[s]="gray"
    while Q:
        f=heapq.heappop(Q)

        u=f[1]
        color[u]="Black"
        if f[0]>d[u]:
            continue
        for i in range(len(M[u])):
            if color[M[u][i][1]]!="Black":
                v=M[u][i][1]
                if d[v]>d[u]+M[u][i][0]:
                    d[v]=d[u]+M[u][i][0]
                    color[M[u][i][1]]="gray"
                    heapq.heappush(Q,(d[M[u][i][1]],M[u][i][1]))
                    
dijkstra(0)

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

Python: from heapq import*
I=float("inf")
def m():
 n=int(input())
 A=[]
 for _ in range(n):
  e=list(map(int,input().split()))
  A+=[zip(e[2::2],e[3::2])]
 d=[0]+[I]*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()

Python: #coding:utf-8
dic = {}
nil = -1

class Doubly:
    def __init__(self,key,l=nil,r=nil):
        self.l = l
        self.r = r
        self.key = key

    def Insert(self,key):
        obj = Doubly(key)
        obj.l = fake
        fakeR = fake.r
        fake.r = obj
        obj.r = fakeR
        fakeR.l = obj
        if key in dic.keys():
            dic[key].append(obj)
        else:
            dic[key] = [obj]
    def deleteFirst(self):
        fakeR = fake.r
        fake.r = fakeR.r
        fakeR.r.l = fake
        key = fakeR.key
        if dic != {}:
            dic[key].pop(0)
            if dic[key] == []:
                del dic[key]

    def deleteLast(self):
        fakeL = fake.l
        fake.l = fakeL.l
        fakeL.l.r = fake
        key = fakeL.key
        if dic != {}:
            dic[key].pop(0)
            if dic[key] == []:
                del dic[key]
        

    def Delete(self,target):
        if target in dic.keys():
            obj = dic[target].pop(0)
            objL = obj.l
            objR = obj.r
            objL.r = objR
            objR.l = objL
            if dic[target] == []:
                del dic[target]
        


n = int(input())

fake = Doubly(nil)
fake.l = fake
fake.r = fake


for i in range(n):
    data = list(input().split())
    order = data[0]
    if order == "insert":
        Doubly.Insert(Doubly, int(data[1]))
    elif order == "delete":
        Doubly.Delete(Doubly, int(data[1]))
    elif order == "deleteFirst":
        Doubly.deleteFirst(Doubly)
    else:
        Doubly.deleteLast(Doubly)

obj = fake.r
List = []
while obj.key != -1:
    List.append(str(obj.key))
    obj = obj.r

print(" ".join(List))

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
input:
5
0 3 2 3 3 1 1 2
1 2 0 2 3 4
2 3 0 3 3 1 4 1
3 4 2 1 0 1 1 4 4 3
4 2 2 1 3 3

output:
0 0
1 2
2 2
3 1
4 3
"""

import sys
import heapq as hp

WHITE, GRAY, BLACK = 0, 1, 2


def generate_adj_table(v_table):
    for each in v_table:
        v_index, v_adj_length, *v_adj_list = map(int, each)
        # assert len(v_adj_list) == v_adj_length * 2
        for pair in zip(v_adj_list[::2], v_adj_list[1::2]):
            init_adj_table[v_index][pair[0]] = pair[1]

    return init_adj_table


def dijkstra_path_heap():
    # path search init
    distance[init_vertex] = 0
    path_heap = []
    # heapq: rank by tuple[0], at here it's d[u]
    hp.heappush(path_heap, (0, init_vertex))

    while path_heap:
        current = hp.heappop(path_heap)[1]

        color[current] = BLACK

        for adj, cost in adj_table[current].items():
            if color[adj] is not BLACK:
                # alt: d[u] + w[u,v]
                alt_path = distance[current] + cost
                if alt_path < distance[adj]:
                    # update path_list
                    distance[adj] = alt_path
                    # update heap
                    hp.heappush(path_heap, (alt_path, adj))
                    color[adj] = GRAY
                    parents[adj] = current

    return distance


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices = int(_input[0])
    v_info = map(lambda x: x.split(), _input[1:])
    # assert len(init_vertices_table) == vertices_num

    distance = [float('inf')] * vertices
    parents = [-1] * vertices
    color = [WHITE] * vertices
    init_adj_table = tuple(dict() for _ in range(vertices))
    init_vertex = 0

    adj_table = generate_adj_table(v_info)
    ans = dijkstra_path_heap()
    for i, v in enumerate(ans):
        print(i, v)