Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

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

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

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, d[i])
	}
	wtr.Flush()
}

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


class SingleSourceShortestPath(object):
    __slots__ = ('adj_table', 'distance', 'parent', 'visited')

    def __init__(self, in_data):
        v_num = int(in_data[0])
        vertices = map(lambda x: x.split(), in_data[1:])
        adj_table = tuple(dict() for _ in range(v_num))

        for v_info in vertices:
            source, v_adj_length, *v_adj_list = map(int, v_info)
            # assert len(v_adj_list) == v_adj_length * 2
            for target, cost in zip(v_adj_list[::2], v_adj_list[1::2]):
                adj_table[source][target] = cost

        self.adj_table = adj_table
        self.distance = [float('inf')] * v_num
        self.parent = [-1] * v_num
        self.visited = [WHITE] * v_num

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

        while path_heap:
            csp, current = hp.heappop(path_heap)
            self.visited[current] = BLACK

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

        return self.distance


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    case = SingleSourceShortestPath(in_data=_input)
    ans = case.path_heap_dijkstra(root=0)
    for i, v in enumerate(ans):
        print(i, v)

Python: # -*- coding: utf-8 -*-
from heapq import heappop, heappush

N = int(input())
INF = float("inf")
d = [INF for n in range(N)]
d[0] = 0
adj = [[] for _ in range(N)]

for n in range(N):
    inp = tuple(map(int, input().split()))
    for i in range(inp[1]):
        adj[n] = list(zip(inp[2::2], inp[3::2]))

heap = [[0, 0]]

while len(heap):
    pcost, p = heappop(heap)
    
    for v, c in adj[p]:
        new_cost = pcost + c
        if new_cost < d[v]:
            d[v] = new_cost
            heappush(heap, [new_cost, v])

for n in range(N):
    print("{} {}".format(n, d[n]))

Python: from heapq import heappush, heappop
import sys
INFTY=sys.maxsize

def readinput():
    n=int(input())
    nList=[]
    for _ in range(n):
        nList.append([])
    for _ in range(n):
        l=list(map(int,input().split()))
        i=l[0]
        k=l[1]
        for j in range(k):
            v=l[2+j*2]
            c=l[2+j*2+1]
            nList[i].append([v,c])
    return n,nList

def dijkstra(s,n,nList):
    WHITE=0
    GRAY=1
    BLACK=2
    color=[WHITE]*n
    d=[INFTY]*n

    HQ=[]

    d[s]=0
    heappush(HQ,(d[s],s))

    while(len(HQ)>0):
        du,u=heappop(HQ)
        color[u]=BLACK

        if d[u]<du:
            continue

        for (v,vw) in nList[u]:
            if color[v]!=BLACK:
                if d[u] + vw < d[v]:
                    d[v] = d[u] + vw
                    color[v]=GRAY
                    heappush(HQ, (d[v], v))
    return d


def main(n,nList):
    d=dijkstra(0,n,nList)    
    for i in range(n):
        print('{} {}'.format(i,d[i]))

    return

if __name__=='__main__':
    n,nList=readinput()
    main(n,nList)

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])