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: from sys import maxsize
from heapq import heappop, heappush


class Node:
    WHITE = 0
    GRAY = 1
    BLACK = 2

    def __init__(self):
        self.adjs = []
        self.color = Node.WHITE
        self.dist = maxsize

    def __lt__(self, other):
        return self.dist < other.dist

    def __repr__(self):
        return "Node({},{},{})".format(self.adjs, self.color, self.dist)


def read_adj():
    n = int(input())
    nodes = [Node() for _ in range(n)]

    for i in range(n):
        u, _, *rest = [int(x) for x in input().split()]
        for i in range(0, len(rest) - 1, 2):
            nodes[u].adjs.append((rest[i], rest[i+1]))

    return nodes


def shortest_path(nodes):
    h = []

    nodes[0].dist = 0
    nodes[0].color = Node.GRAY
    heappush(h, (0, 0))

    while len(h) > 0:
        min_dist, min_node = heappop(h)

        nodes[min_node].color = Node.BLACK
        if nodes[min_node].dist < min_dist:
            continue

        for adj, c in nodes[min_node].adjs:
            if nodes[adj].color == Node.BLACK:
                continue
            if nodes[min_node].dist + c < nodes[adj].dist:
                nodes[adj].dist = nodes[min_node].dist + c
                nodes[adj].color = Node.GRAY
                heappush(h, (nodes[adj].dist, adj))


def print_dist(nodes):
    for u, n in enumerate(nodes):
        print(u, n.dist)


def main():
    nodes = read_adj()
    print(nodes)
    shortest_path(nodes)
    print_dist(nodes)


if __name__ == '__main__':
    main()

Python: #!/usr/bin/env python
from __future__ import division, print_function
from sys import stdin, maxint
from operator import itemgetter
from heapq import heappush, heappop, heapify


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

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

    distances = [[maxint, i] for i in xrange(num)]
    distances[0][0] = 0
    V = set(xrange(1, num))
    W = []#distances[1:]
    mark = set()
    index = 0

    while V:
        for v, cost in edges[index]:
            if v not in V:
                continue
            cost += distances[index][0]
            if distances[v][0] > cost:
                distances[v][0] = cost
                if v not in mark:
                    W.append(distances[v])
                    mark.add(v)

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

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

main()

Python: import heapq
import sys
readline = sys.stdin.readline
def dijkstra(n):
    inf = 10 ** 6 + 1
    dist = [0] + [inf] * (n - 1)
    q = [(0, 0)]
    while q:
        u = heapq.heappop(q)[1]
        for (v, c) in edge[u]:
            alt = dist[u] + c
            if dist[v] > alt:
                dist[v] = alt
                heapq.heappush(q, (alt, v))
    return dist
n = int(input())
edge = [[]] * n
for _ in range(n):
    l = list(map(int, readline().split()))
    edge[l[0]] = (e for e in zip(l[2::2], l[3::2]))
for i, c in enumerate(dijkstra(n)):
    print(i, c)

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


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

    while V:
        for v, cost in L[index]:
            if v not in V:
                continue
            weight[v][1] = min(weight[v][1], cost + weight[index][1])

        W.sort(key=itemgetter(1), reverse=True)
        index = W.pop()[0]

        V.remove(index)

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


main()

Python: # Graph II - Single Source Shortest Path II
def dijkstra(length, adj_list):
    INFTY = float('inf')
    d = [INFTY for _ in range(length)]
    d[0] = 0
    Q = [i for i in range(length)]
    while Q:
        idx = INFTY
        minv = INFTY
        for q in Q:
            if d[q] < minv:
                idx, minv = q, d[q]
        u = Q.pop(Q.index(idx))
        for v in adj_list[u]:
            if d[v[0]] > d[u] + v[1]:
                d[v[0]] = d[u] + v[1]
    return d

n = int(input())
adj_list = [set() for _ in range(n)]
for _ in range(n):
    ss = list(map(int, input().split()))
    u, k = ss[0], ss[1]
    for i in range(k):
        vi,ci = ss[2*i+2], ss[2*i+3]
        adj_list[u].add((vi,ci))
d = dijkstra(n, adj_list)
for i,v in enumerate(d): print(i,v)