Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const BIG_COST = 200000

type Path struct {
	node int
	cost int
}

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

	nNodes := scanInt(sc)

	// 各頂点につながる頂点一覧を得るための隣接リスト
	graph := make([][]Path, nNodes)

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[i] = make([]Path, k)
		for d := 0; d < k; d++ {
			graph[u][d] = Path{
				node: scanInt(sc),
				cost: scanInt(sc),
			}
		}
	}

	// 0 から各頂点への最小コストを保存する配列
	minCosts := make([]int, nNodes)

	minCosts[0] = 0
	for i := 1; i < nNodes; i++ {
		minCosts[i] = BIG_COST
	}

	// 各頂点が調査済みかどうかを保持する配列
	checked := make([]bool, nNodes)

	// 最小コストのパスを高速に取得するためのヒープ。
	// コストが小さいものほどルートに来るようにする。
	heap := NewHeap(func(a, b Path) bool {
		return a.cost < b.cost
	})

	heap.insert(Path{node: 0, cost: 0})
	for heap.size > 0 {
		u := heap.extractMax()

		// 隣接行列を使っていた時とは違い、ヒープには
		// 同じノードへのパスが複数含まれうる。そのため既によりコストの低い
		// パスが見つかっている場合は無視する。
		if minCosts[u.node] < u.cost {
			continue
		}

		checked[u.node] = true

		for _, v := range graph[u.node] {
			cost := v.cost + u.cost
			if !checked[v.node] && cost < minCosts[v.node] {
				minCosts[v.node] = cost
				heap.insert(Path{node: v.node, cost: cost})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range minCosts {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

// --- From ALDS1_9_C: Priority Queue

type Heap struct {
	size   int
	heap   []Path
	isHigh func(a, b Path) bool
}

func NewHeap(isHigh func(a, b Path) bool) Heap {
	heap := make([]Path, 1) // 先頭は不使用
	return Heap{size: 0, heap: heap, isHigh: isHigh}
}

func (h *Heap) insert(v Path) {
	h.size += 1
	if h.size > len(h.heap)-1 {
		h.heap = append(h.heap, v)
	} else {
		h.heap[h.size] = v
	}

	for i := h.size; i > 1; {
		parent := i / 2
		if h.isHigh(h.heap[parent], h.heap[i]) {
			break
		}
		h.heap[i], h.heap[parent] = h.heap[parent], h.heap[i]
		i = parent
	}
}

func (h *Heap) extractMax() Path {
	if h.size <= 0 {
		panic("cannot extract from empty heap")
	}

	max := h.heap[1]
	h.heap[1] = h.heap[h.size]
	h.size -= 1
	h.maxHeapify(1)

	return max
}

func (h *Heap) maxHeapify(idx int) {
	left := idx * 2
	right := left + 1
	largest := idx

	if left <= h.size {
		if h.isHigh(h.heap[left], h.heap[idx]) {
			largest = left
		}
		if right <= h.size && h.isHigh(h.heap[right], h.heap[largest]) {
			largest = right
		}
	}

	if largest != idx {
		h.heap[idx], h.heap[largest] = h.heap[largest], h.heap[idx]
		h.maxHeapify(largest)
	}
}

Python: import heapq

INF = 1e9

n = int(input())
adj_list = [[]] * n

for u in range(n):
    U = list(map(int, input().split()[2:]))
    adj_list[u] = zip(U[0::2], U[1::2]) # adj_list[u] = (v, cost)


def dijkstra(x):
    d = [INF] * x
    d[0] = 0
    isVisited = [False] * x
    hq = [(0, 0)] # (distance, v)??????????????¬??????????????????(key, ????´?)???????????????push, pop?????????
    
    while hq:
        u = heapq.heappop(hq)[1]
        isVisited[u] = True
        
        for v, c in adj_list[u]:
            if not isVisited[v] and d[v] > d[u] + c:
                d[v] = d[u] + c
                heapq.heappush(hq, (d[u] + c, v))
                
    return d

for i, di in enumerate(dijkstra(n)):
    print(i,di)

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


def heap_increase_key(heap, i):
    parent = i // 2
    while i > 1 and heap[parent][0] > heap[i][0]:
        heap[i], heap[parent] = heap[parent], heap[i]
        i //= 2
        parent = i // 2


def min_heapify(heap, i):
    heap_size = len(heap)-1
    L = i * 2
    R = L + 1
    if L <= heap_size and heap[L][0] < heap[i][0]:
        smallest = L
    else:
        smallest = i
    if R <= heap_size and heap[R][0] < heap[smallest][0]:
        smallest = R
    if smallest != i:
        heap[i], heap[smallest] = heap[smallest], heap[i]
        min_heapify(heap, smallest)


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))
    W = [0] + weight[1:]
    index = 0

    while V:
        i = maxint
        for v, cost in L[index]:
            if v not in V:
                continue
            cost += weight[index][0]
            if weight[v][0] > cost:
                weight[v][0] = cost
                heap_increase_key(W, W.index(weight[v]))
            #weight[v][0] = min(weight[v][0], cost + weight[index][0])

        index = W.pop(1)[1]
        min_heapify(W, 1)
        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
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 = [[maxint, i] for i in xrange(num)]
    weight[0][0] = 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][0] = min(weight[v][0], cost + weight[index][0])

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

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


main()

Python: from heapq import heappush, heappop

INF = 10000 * 100000

def dijkstra(s: int):
	d[s] = 0
	H = []
	for v in range(n):
		heappush(H, (d[v], v))
	while len(H) >= 1:
		_, u = heappop(H)
		color[u] = "BLACK"
		for v, c in M[u]:
			if color[v] != "BLACK" and d[u] + c < d[v]:
				d[v] = d[u] + c
				pi[v] = u
				color[v] = "GRAY"
				heappush(H, (d[v], v))

if __name__ == "__main__":
	n = int(input())
	G = []
	M = [[] for _ in range(n)]
	color = ["WHITE" for _ in range(n)]
	d = [INF for _ in range(n)]
	pi = [None for _ in range(n)]

	for _ in range(n):
		l = list(map(int, input().split()))
		u = l[0]
		k = l[1]
		for i in range(k):
			v = l[2 * (i + 1)]
			c = l[2 * (i + 1) + 1]
			M[u].append([v, c])
	dijkstra(0)
	for v in range(n):
		print(f"{v} {d[v]}")

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

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

searched = [False for _ in range(N)]
searched[0] = True

for n in range(N):
    inp = tuple(map(int, input().split()))
    assert n == inp[0]
    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)
    searched[p] = True
    
    if d[p] < pcost:
        continue
    
    for v, c in adj[p]:
        if not searched[v]:
            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]))