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
from __future__ import division, print_function
from sys import stdin, maxint
from operator import itemgetter
import heapq


def main():
    num = int(stdin.readline())

    L = []
    for _ in xrange(num):
        it = iter(int(s) for s in stdin.readline().split()[1:])
        L.append([(next(it), next(it)) for _ in xrange(next(it))])

    weight = [[maxint, i] for i in xrange(num)]
    weight[0][0] = 0
    V = set(xrange(1, num))
    A = set(v for v, cost in L[0])
    W = weight[1:]
    index = 0

    while V:
        swap = False
        for v, cost in L[index]:
            if v not in A:
                continue
            weight[v][0] = min(weight[v][0], cost + weight[index][0])


        a = min(W, key=itemgetter(0))
        index = a[1]
        W.remove(a)

        A.update(v for v, cost in L[index])
        A.remove(index)
        V.remove(index)

    for d, i in weight:
        print(i, d)


main()

Python: #!/usr/bin/env python
from __future__ import division, print_function
from sys import stdin, maxint


def main():
    num = int(stdin.readline())

    L = []
    for _ in xrange(num):
        it = iter(int(s) for s in stdin.readline().split()[1:])
        L.append([(next(it), next(it)) for _ in xrange(next(it))])

    weight = [maxint] * num
    weight[0] = 0
    V = set(xrange(1, num))
    index = 0

    def compare(i):
        return weight[i]

    while V:
        for v, cost in L[index]:
            if v not in V:
                continue
            weight[v] = min(weight[v], cost + weight[index])

        index = min(V, key=compare)
        V.remove(index)

    for i, d in enumerate(weight):
        print(i, d)


main()

Python: import sys

f_i = sys.stdin

n = int(f_i.readline())

adj = [[]] * n
for x in f_i:
    x = list(map(int, x.split()))
    adj[x[0]] = [c_v for c_v in zip(x[3::2], x[2::2])]

import heapq

def dijkstra():
    PQ = [(0, 0)]
    isVisited = [False] * n
    distance = [999900001] * n

    distance[0] = 0
    
    while PQ:
        uc = heapq.heappop(PQ)
        u = uc[1]

        if uc[0] > distance[u]:
            continue

        isVisited[u] = True
        
        for c, v in adj[u]:
            if isVisited[v] == True:
                continue
            t_cost = distance[u] + c
            if t_cost < distance[v]:
                distance[v] = t_cost
                heapq.heappush(PQ, (t_cost, v))

    for v, d in enumerate(distance):
        print(v, d)


dijkstra()

Python: #coding:utf-8
inf = 1000000
n = int(input())
M = [[inf for i in range(n)] for j in range(n)]
vwMtrx = []
for i in range(n):
    data = list(map(int,input().split()))
    u = data[0]
    k = data[1]
    col = []
    for j in range(0,2*k,2):
        v, w = data[j+2], data[j+3]
        M[u][v] = w
        col.append([v,w])
    vwMtrx.append(col)

def dijkstra(s):
    color = ["white" for i in range(n)]
    d = [inf for i in range(n)]
    p = [-1 for i in range(n)]
    d[s] = 0
    Q = [[s,0]]
    while Q != []:
        u = min(Q, key=lambda x:x[1])
        Q = [List for List in Q if List != u]
        u = u[0]
        color[u] = "black"

        vwList = vwMtrx[u]
        
        for vw in vwList:
            v,w = vw[0],vw[1]
            if color[v] != "black" and M[u][v] != inf:
                if d[u] + M[u][v] < d[v]:
                    d[v] = d[u] + M[u][v]
                    p[v] = u
                    color[v] = "gray"
                    Q.append([v, d[v]])

    return d

dList = dijkstra(0)
for i, d in enumerate(dList):
    print(i,d)

Python: import heapq

n = int(input())
maxim = 100010
adj = [[] for _ in range(n)]

for _ in range(n):
    u, k, *v = map(int, input().split())
    if k == 0:
        adj[u].append((0,0))
    for i in range(k):
        adj[u].append((v[i*2+1], v[i*2]))

def dijkstra():
    global adj
    PQ = []
    heapq.heapify(PQ)
    color = ['W']*n
    d = [maxim]*n
    d[0] = 0
    heapq.heappush(PQ, (0, 0))
    color[0] = 'G'

    while PQ:
        f = heapq.heappop(PQ)
        u = f[1]
        color[u] = 'B'
        if d[u] < f[0]*-1:
            continue
        for j in range(len(adj[u])):
            v = adj[u][j][1]
            if color[v] == 'B':
                continue
            if d[v] > d[u]+adj[u][j][0]:
                d[v] = d[u]+adj[u][j][0]
                heapq.heappush(PQ, (d[v], v))
                color[v] = 'G'
    return d

D = dijkstra()
for i, x in enumerate(D):
    print(i, x)