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

	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: # coding: utf-8
# Your code here!
import heapq

WHITE = 0
GRAY = 1
BLACK = 2

INF = 2000000000


def dijkstra():
    PQ = []
    heapq.heapify(PQ)
    color = [WHITE] * n
    d = [INF] * n
    
    d[0] = 0
    heapq.heappush(PQ, (0, 0))
    color[0] = GRAY
    
    while len(PQ) != 0:
        
        f = heapq.heappop(PQ)
        u = f[1]
        color[u] = BLACK
        
        if d[u] < f[0]:
            continue
        
        for j in range(len(adj[u])):
            v = adj[u][j][0]
            if color[v] == BLACK:
                continue
            if d[v] > d[u] + adj[u][j][1]:
                d[v] = d[u] + adj[u][j][1]
                heapq.heappush(PQ, (d[v], v))
                color[v] = GRAY
    for i in range(n):
        print(i, d[i])


n = int(input())

adj = [[] for j in range(n)]
for i in range(n):
    nums=list(map(int,input().split()))
    for j in range(nums[1]):
        adj[nums[0]].append((nums[2*j+2], nums[2*j+3]))
        

dijkstra()

Python: N = int(input())

E = [None] * N
for _ in range(N):
    u, k, *vs = map(int, input().split())
    E[u] = []
    for i in range(k):
        v, c = vs[i*2], vs[i*2+1]
        E[u].append((v, c))

import heapq

vis = [False] * N
inf = 1e9
d = [inf] * N
d[0] = 0
pq = [(0, 0)]
while pq:
    nv, ni = heapq.heappop(pq)
    if nv > d[ni]:
        continue
    d[ni] = nv
    vis[ni] = True
    for v, c in E[ni]:
        nc = d[ni] + c
        if not vis[v] and nc < d[v]:
            heapq.heappush(pq, (nc, v))

for v in range(N):
    print(v, d[v])

Python: # -*- coding: utf-8 -*-
from heapq import heappop, heappush
def inpl(): return list(map(int, input().split()))
INF = float("inf")
N = int(input())
G = []
for _ in range(N):
    I = inpl()
    G.append(zip(*[I[3::2], I[2::2]]))

def dijkstra(G):
    C = [INF]*(N)
    C[0] = 0
    visited = [False] * (N)
    Q = [[0, 0]]

    while Q:
        c, u = heappop(Q)
        if C[u] < c:
            continue
        visited[u] = True
        for d, v in G[u]:
            if visited[v]:
                continue
            e = c + d
            if e < C[v]:
                C[v] = e
                heappush(Q, [e, v])
    return C

for i, c in enumerate(dijkstra(G)):
    print(i, c)

Python: import heapq as hp

INF = 1000000

def diikstraMethd(G, s):
    # ?????????
    n = len(G)
    d = [INF for _ in range(n)]
    d[s] = 0
    PQ = [(d[s], s)]

    while PQ:
        u = hp.heappop(PQ)[1]
        for v, c in G[u]:
            alt = d[u] + c
            if d[v] > alt:
                d[v] = alt
                hp.heappush(PQ, (alt, v))

    return d


if __name__ == '__main__':
    n = int(input())
    G = [ [] for _ in range(n)]
    for _ in range(n):
        tmp = list(map(int, input().split()))
        u = tmp.pop(0)
        k = tmp.pop(0)
        for i in range(k):
            v = tmp.pop(0)
            c = tmp.pop(0)
            G[u].append((v, c))

    d = diikstraMethd(G, 0)

    for i in range(n):
        print('{0} {1}'.format(i, d[i]))

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


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, v] for v in xrange(num)]
    distances[0][0] = 0
    V = set(xrange(1, num))
    candidate = []
    index = 0

    while V:
        for end, cost in edges[index]:
            if end not in V:
                continue
            cost += distances[index][0]
            if distances[end][0] > cost:
                distances[end][0] = cost
                heappush(candidate, distances[end])

        index = heappop(candidate)[1]
        V.discard(index)

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


main()

Python: #coding:utf-8
import numpy as np

n = int(input())
inf = 1000000000000000

def minHeapify(Q,i):
    H = len(Q)
    l = 2*i
    r = 2*i + 1
    if l < H and Q[l][1] < Q[i][1]:
        smallest = l
    else:
        smallest = i
    if r < H and Q[r][1] < Q[smallest][1]:
        smallest = r

    if smallest != i:
        Q[i], Q[smallest] = Q[smallest], Q[i]
        minHeapify(Q,smallest)

def buildMinHeap(Q):
    H = len(Q)
    for i in range(H // 2, -1, -1):
        minHeapify(Q,i)

def Insert(Q,key):
    v = key[0]
    Q.append([v,inf])
    lens = len(Q)
    heapIncreaseKey(Q,lens-1,key)

def heapIncreaseKey(Q,i,key):
    Q[i][1] = key[1]
    while i > 0 and Q[i // 2][1] > Q[i][1]:
        Q[i], Q[i // 2] = Q[i // 2], Q[i]
        i //= 2

def heapExtractMin(Q):
    H = len(Q)
    minv = Q[0][0]
    Q[0] = Q[H-1]
    Q.pop()
    minHeapify(Q,0)
    return minv




def dijkstra(s):
    color = ["white" for i in range(n)]
    d = [inf for i in range(n)]
    d[s] = 0
    Q = [[s,0]]
    while Q != []:
        u = heapExtractMin(Q)
        color[u] = "black"
        for vw in mtrx[u]:
            [v,w] = vw
            if color[v] != "black":
                if d[u] + w < d[v]:
                    d[v] = d[u] + w
                    color[v] = "gray"
                    Insert(Q,[v,d[v]])
    return d



mtrx = [[] for i in range(n)]
for i in range(n):
    col = list(map(int,input().split()))
    u,k = col[0], col[1]
    for j in range(k):
        [v,w] = col[2*j+2: 2*j+4]
        mtrx[u].append([v,w])



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