Go: package main

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

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

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

// we want the ascending-priority-queue.
// So we use less than here.
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 = j
	pq[j].index = i
}

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
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0
	heap.Init(&pq)

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

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

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

Python: import heapq
from collections import deque
from enum import Enum
import sys
import math
from _heapq import heappush, heappop

#------------------------------------------#

BIG_NUM = 2000000000
HUGE_NUM = 9999999999999999
MOD = 1000000007
EPS = 0.000000001

#------------------------------------------#

class Edge:
    def __init__(self,arg_to,arg_cost):
        self.to = arg_to
        self.cost = arg_cost

class Info:
    def __init__(self,arg_node_id,arg_sum_cost):
        self.node_id = arg_node_id
        self.sum_cost = arg_sum_cost

    def __lt__(self,arg):
        return self.sum_cost < arg.sum_cost


V = int(input())
min_dist = [BIG_NUM]*V
G = [[] for i in range(V)]

for loop in range(V):
    node_id,tmp_num,*table = list(map(int,input().split()))
    for i in range(0,len(table),2):
        G[node_id].append(Edge(table[i],table[i+1]))


min_dist[0] = 0
Q = []

heappush(Q, Info(0,0))

while len(Q) > 0:
    info = heappop(Q)
    if info.sum_cost > min_dist[info.node_id]:
        continue
    for edge in G[info.node_id]:
        if min_dist[edge.to] > info.sum_cost+edge.cost:
            min_dist[edge.to] = info.sum_cost+edge.cost
            heappush(Q, Info(edge.to,min_dist[edge.to]))


for i in range(V):
    print("%d %d"%(i,min_dist[i]))

Python: import heapq
from collections import deque
from enum import Enum
import sys
import math
from _heapq import heappush, heappop

#------------------------------------------#

BIG_NUM = 2000000000
HUGE_NUM = 9999999999999999
MOD = 1000000007
EPS = 0.000000001

#------------------------------------------#

class Edge:
    def __init__(self,arg_to,arg_cost):
        self.to = arg_to
        self.cost = arg_cost

class Info:
    def __init__(self,arg_node_id,arg_sum_cost):
        self.node_id = arg_node_id
        self.sum_cost = arg_sum_cost

    def __lt__(self,arg):
        return self.sum_cost < arg.sum_cost


V = int(input())
min_dist = [BIG_NUM]*V
G = [[] for i in range(V)]

for loop in range(V):
    node_id,tmp_num,*table = list(map(int,input().split()))
    for i in range(0,len(table),2):
        G[node_id].append(Edge(table[i],table[i+1]))


min_dist[0] = 0
Q = []

heappush(Q, Info(0,0))

while len(Q) > 0:
    info = heappop(Q)
    if info.sum_cost > min_dist[info.node_id]:
        continue
    for edge in G[info.node_id]:
        if min_dist[edge.to] > info.sum_cost+edge.cost:
            min_dist[edge.to] = info.sum_cost+edge.cost
            heappush(Q, Info(edge.to,min_dist[edge.to]))


for i in range(V):
    print("%d %d"%(i,min_dist[i]))

Python: INFTY = 1 << 21
WHITE = 0
GRAY = 1
BLACK = 2
 
n = int(input())
M = [list(map(int, input().split())) for i in range(n)]
for u in range(0, n):
    U = list(map(int, input().split()[2:]))
    for j in range(0, len(U), 2):
        M[u][U[j]] = U[j + 1]
d = [INFTY for i in range(n)]
color = [WHITE for i in range(n)]

def dijkstra():
    global M, d, color, n
    d[0] = 0
    color[0] = GRAY
    while(1):
        minv = INFTY
        u = -1
        for i in range(n):
            if (minv > d[i] and color[i] != BLACK):
                u = i
                minv = d[i]
        if (u == -1):
            break
        color[u] = BLACK
        for v in range(n):
            if (color[v] != BLACK and M[u][v] != INFTY):
                if (d[v] > d[u] + M[u][v]):
                    d[v] = d[u] + M[u][v]
                    color[v] = GRAY
    for i in range(n):
        print(str(i), (-1 if d[i] == INFTY else str(d[i])))
dijkstra()

Python: from collections import namedtuple
import heapq

Edge = namedtuple('Edge', ('fr', 'to', 'cost'))
inf = int(1e9)


def bellman_ford(n, start, edges):
    dists = [inf for _ in range(n)]
    dists[start] = 0
    while True:
        updated = False
        for e in edges:
            if dists[e.fr] != inf and dists[e.fr] + e.cost < dists[e.to]:
                updated = True
                dists[e.to] = dists[e.fr] + e.cost

        if not updated:
            break

    return dists


def dijkstra(n, costs):
    dists = [inf for _ in range(n)]
    dists[0] = 0

    queue = []
    for (i, d) in enumerate(dists):
        heapq.heappush(queue, (d, i))

    while len(queue) > 0:
        d, i = heapq.heappop(queue)
        if d > dists[i]:
            continue

        for v in range(n):
            if v == i or costs[i][v] == inf:
                continue

            if dists[i] + costs[i][v] < dists[v]:
                dists[v] = dists[i] + costs[i][v]
                heapq.heappush(queue, (dists[v], v))

    return dists


def warshall_floyd(n, costs):
    dists = [[costs[i][j] if i != j else 0 for i in range(n)] for j in range(n)]

    for k in range(n):
        for i in range(n):
            for j in range(n):
                dists[i][j] = min(dists[i][j], dists[i][k] + dists[k][j])

    return dists


n = int(input())

m = [[inf for _ in range(n)] for _ in range(n)]
es = []
for i in range(n):
    fs = list(map(int, input().split()))
    ne = fs[1]
    for j in range(ne):
        v = fs[2+2*j]
        c = fs[2+2*j+1]
        m[i][v] = c
        es.append(Edge(i, v, c))


# d = bellman_ford(n, 0, es)
# d = dijkstra(n, m)
d = warshall_floyd(n, m)
for (i, di) in enumerate(d[0]):
    print(i, di)

Python: n = int(input())

graph = [[] for i in range(n)]

for i in range(n):
    a = list(map(int, input().split()))
    for j in range(a[1]):
        graph[a[0]].append(a[2+j*2:4+j*2])  #[頂点, cost]

memo = [10**10 for i in range(n)]
memo[0] = 0

import heapq
q = []
heapq.heappush(q, (0, 0))   #(それまでのcost, 頂点)
while len(q) != 0:
    top = heapq.heappop(q)
    for g in graph[top[1]]:
        cost = top[0] + g[1]
        if memo[g[0]] > cost:
            memo[g[0]] = cost
            heapq.heappush(q, (cost, g[0]))

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