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
	heap.Init(&pq)

	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: from heapq import *
n = int(input())
INF = float("inf")
adj = [[] for _ in range(10**4+4)]
for _ in range(n):
    a,*b = map(int,input().split())
    if b[0] != 0:
        c = b[1:]
        for i in range(len(c)//2):
            k,w = c[2*i],c[2*i+1]
            adj[a].append((k,w))
H = []
heapify(H)
searched = [0]*n
d = [INF]*n
d[0] = 0
heappush(H, (0,0))
while H:
    f = heappop(H)
    u = f[-1]
    searched[u] = 1
    if d[u] < f[0]:
        continue
    for j in range(len(adj[u])):
        v = adj[u][j][0]
        if searched[v]:
            continue
        if d[v] > d[u]+adj[u][j][-1]:
            d[v] = d[u]+adj[u][j][-1]
            heappush(H,(d[v],v))
for i in range(n):
    ans = -1 if d[i] == INF else d[i]
    print(i,ans)

Python: from collections import deque

n = int(input())
g = []
d = [10**10] * n
d[0] = 0

for i in range(n):
    temp = list(map(int, input().split()))
    k = temp[1]
    temp = temp[2:]
    adj = []
    for j in range(k):
        v, c = temp[j*2], temp[j*2+1]
        adj.append([v, c])
    g.append(adj)

# for i in range(n):
#     print(g[i])

q = deque()
# Add tupple of prev and adj into Queue
q.append((0, g[0]))
done = set()

while q:
    node = q.popleft()
    prev = node[0]
    adj = node[1]
    # print('\nadj:', adj)

    for next in adj:
        v = next[0]
        w = next[1]
        # print('v:', v)
        # print('prev:', prev)

        # d[v] = min(d[v], d[prev] + w)
        if d[prev] + w < d[v]:
            d[v] = d[prev] + w
            # Need to add to Queue regardless of it's in done or not,
            # because the shortest path was updated.
            q.append((v, g[v]))
        if v not in done:
            done.add(v)
            q.append((v, g[v]))

# print('d:', d)

for i in range(len(d)):
    print(i, d[i])

Python: from heapq import*
n=int(input())
A=[[]for _ in[0]*n]
for _ in[0]*n:
 e=list(map(int,input().split()))
 for i in range(e[1]):k=2*-~i;A[e[0]]+=[(e[k],e[k+1])]
H=[[0,0]]
d=[0]+[1e6]*n
c=[1]*n
while H:
 f=heappop(H)
 u=f[1]
 c[u]=0
 if d[u]>=f[0]:
  for s in A[u]:
   v=s[0]
   if c[v]and d[v]>d[u]+s[1]:
    d[v]=d[u]+s[1]
    heappush(H,[d[v],v])
for i in range(n):print(i,d[i])

Python: import heapq
from collections import deque
from enum import Enum
import sys
import math
from _heapq import heappush, heappop
import copy
from test.support import _MemoryWatchdog

BIG_NUM = 2000000000
HUGE_NUM = 99999999999999999
MOD = 1000000007
EPS = 0.000000001
sys.setrecursionlimit(100000)


class Edge:
    def __init__(self,arg_to,arg_dist):
        self.to = arg_to
        self.dist = arg_dist

class Info:
    def __init__(self,arg_node_id,arg_sum_dist):
        self.node_id = arg_node_id
        self.sum_dist = arg_sum_dist

    def __lt__(self,another):
        return self.sum_dist < another.sum_dist


V = int(input())
G = [[] for _ in range(V)] #隣接グラフ
min_dist = [BIG_NUM]*V

for _ in range(V):
    node_id,num_adj,*tmp_array = list(map(int,input().split()))
    for i in range(0,len(tmp_array),2):
        G[node_id].append(Edge(tmp_array[i],tmp_array[i+1]))

min_dist[0] = 0
Q = []
heappush(Q, Info(0,0))

while len(Q) > 0:
    info = heappop(Q)
    if info.sum_dist > min_dist[info.node_id]:continue
    for e in G[info.node_id]:
        if min_dist[e.to] > info.sum_dist+e.dist:
            min_dist[e.to] = info.sum_dist+e.dist
            heappush(Q, Info(e.to,min_dist[e.to]))

for i in range(V):
    print("%d %d"%(i,min_dist[i]))

Python: import sys
from heapq import*
e=sys.stdin.readline
I=float("inf")
def m():
 n=int(e())
 A=[]
 for _ in[0]*n:
  b=list(map(int,e().split()))
  A+=[zip(b[2::2],b[3::2])]
 d=[0]+[I]*n
 H=[(0,0)]
 while H:
  u=heappop(H)[1]
  for v,c in A[u]:
   t=d[u]+c
   if d[v]>t:
    d[v]=t
    heappush(H,(t,v))
 print('\n'.join(f'{i} {d[i]}'for i in range(n)))
m()

Python: def dijkstra(n):
    inf = 10 ** 6 + 1
    dist = [0] + [inf] * (n - 1)
    visited = [False] * n

    while not all(visited):
        dmin = inf
        for i, (d, v) in enumerate(zip(dist, visited)):
            if dmin > d and not v:
                dmin, u = d, i
        visited[u] = True
        for (v, c) in edge[u]:
            if dist[v] > dist[u] + c:
                dist[v] = dist[u] + c
    return dist

n = int(input())
edge = [[]] * n
for _ in range(n):
    l = list(map(int, input().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: # -*- coding: utf-8 -*-

import sys
from heapq import heappush, heappop

sys.setrecursionlimit(10 ** 9)
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
INF=float('inf')

# ダイクストラ(頂点数, 隣接リスト(0-indexed), 始点)
def dijkstra(N: int, nodes: list, src: int) -> list:
    # 頂点[ある始点からの最短距離]
    # (経路自体を知りたい時はここに前の頂点も持たせる)
    res = [float('inf')] * N
    # スタート位置
    que = [(0, src)]
    res[src] = 0
    # キューが空になるまで
    while len(que) != 0:
        # srcからの距離, 現在のノード
        dist, cur = heappop(que)
        # 出発ノードcurの到着ノードでループ
        for nxt, cost in nodes[cur]:
            # 今回の経路のが短い時
            if res[cur] + cost < res[nxt]:
                res[nxt] = res[cur] + cost
                # 現在の移動距離をキューの優先度として、早い方から先に処理するようにする
                heappush(que, (res[nxt], nxt))
    # ノードsrcからの最短距離リストを返却
    return res

N=INT()
nodes=[[] for i in range(N)]
for i in range(N):
    l=LIST()
    u=l[0]
    k=l[1]
    l=l[2:]
    for j in range(0, k*2, 2):
        nodes[u].append((l[j], l[j+1]))

ans=dijkstra(N, nodes, 0)
for i in range(N):
    print(i, ans[i])