Go: package main

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

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := make(map[int]int)
	q[0] = 0
	visited := make(map[int]struct{})
	out := make([]int, n)

	for len(q) > 0 {
		u := top(q)
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			if d, ok := q[uu]; !ok || d > q[u]+c {
				q[uu] = q[u] + c
			}
		}

		out[u] = q[u]
		delete(q, u)
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

func top(q map[int]int) int {
	minu := -1
	min := -1
	for u, d := range q {
		if min < 0 || d < min {
			minu = u
			min = d
		}
	}

	return minu
}

Python: import sys
from heapq import *

MAX_INT= 10 ** 10

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

for _ in range(n):
  commands = sys.stdin.readline().split()
  lst = [ commands[i:i+2] for i in range(2, len(commands), 2)]
  adj_list.append(lst)

def dijkstra():
  # initialization
  visited = [False] * n
  dist_arr = [MAX_INT] * n
  pq = []
  prev = [None] * n

  # append 0 to pqs
  pq = [(0, 0)]
  dist_arr[0] = 0

  while len(pq) > 0:
    dist, idx = heappop(pq)
    visited[idx] = True

    # updating current values in dist
    for edge in adj_list[idx]:
      cur_idx, cur_dist = [ int(e) for e in edge]
      if visited[cur_idx]: continue

      new_dist = dist + cur_dist

      if new_dist < dist_arr[cur_idx]:
        dist_arr[cur_idx] = new_dist
        heappush(pq, (dist_arr[cur_idx], cur_idx))

  return dist_arr

distArr = dijkstra()
for i in range(n):
  print(i, distArr[i])

Python: inf = float('inf')
n = int(input())
g = []
for i in range(n):
    line = list(map(int, input().split()))
    k = line[1]
    c = [inf] * n
    for j in range(k):
        v = line[2 + 2 * j]
        c[v] = line[3 + 2 * j]
    g.append(c)

distance = [inf] * n
distance[0] = 0
visited = [False] * n
current = 0

while not all(visited):
    visited[current] = True
    min_i = 0
    min_d = inf
    for i in range(n):
        if not visited[i]:
            if distance[current] + g[current][i] < distance[i]:
                distance[i] = distance[current] + g[current][i]
            if distance[i] < min_d:
                min_i = i
                min_d = distance[i]
    current = min_i

for i in range(n):
    print(i, distance[i])

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))

vis = [False] * N
inf = 1e9
d = [inf] * N
d[0] = 0
for _ in range(N):
    nv, ni = inf, -1
    for i in range(N):
        if not vis[i] and d[i] < nv:
            nv, ni = d[i], i
    vis[ni] = True
    for v, c in E[ni]:
        d[v] = min(d[v], d[ni] + c)

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

Python: from heapq import heappush,heappop,heapify

n = int(input())
G = [[] for _ in range(n)]
info = []

for i in range(n):
    info =  list(map(int,(input().split())))[2:]
    for j in range(int((len(info))/2)):
        G[i].append((info[2*j],info[2*j+1]))

color = ["white" for _ in range(n)]
dist = [(1<<21) for _ in range(n)]
que = []

def dijkstra():
    dist[0] = 0
    que.append((0,0)) #(dist,node)
    while que:
        heapify(que)
        u = que.pop()[1]
        # print(u)
        color[u] = "black"
        for j in range(len(G[u])):
            if dist[u] + G[u][j][1] < dist[G[u][j][0]]:
                heappush(que,(dist[u] + G[u][j][1],G[u][j][0]))
                dist[G[u][j][0]] = dist[u] + G[u][j][1]

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

dijkstra()

for i,dist in enumerate(dist):
    print(i,dist)

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
input:
5
0 3 2 3 3 1 1 2
1 2 0 2 3 4
2 3 0 3 3 1 4 1
3 4 2 1 0 1 1 4 4 3
4 2 2 1 3 3

output:
0 0
1 2
2 2
3 1
4 3
"""

import sys
import heapq as hp

WHITE, GRAY, BLACK = 0, 1, 2
D_MAX = int(1e7 + 1)


def generate_adj_matrix(v_info):
    for v_detail in v_info:
        v_index = int(v_detail[0])
        v_adj_length = int(v_detail[1])
        v_adj_list = v_detail[2:]
        # assert len(v_adj_list) == v_adj_length * 2
        for j in range(0, v_adj_length * 2, 2):
            init_adj_matrix[v_index][int(v_adj_list[j])] = int(v_adj_list[j + 1])

    return init_adj_matrix


def dijkstra_path():
    # path search init
    start_vertex_index = 0
    path_list[start_vertex_index] = 0
    path_heap = []
    # heapq: compare by tuple[0]
    hp.heappush(path_heap, (path_list[start_vertex_index], start_vertex_index))
    while len(path_heap) >= 1:
        current_vertex_index = hp.heappop(path_heap)[1]

        color[current_vertex_index] = BLACK

        for adj_vertex_index in range(vertices_num):
            current_adj_weight = adj_matrix[current_vertex_index].get(adj_vertex_index, -1)
            if current_adj_weight < 0:
                continue
            elif color[adj_vertex_index] is not BLACK:
                # d[u] + w[u,v]
                alt_path = path_list[current_vertex_index] + current_adj_weight
                if alt_path < path_list[adj_vertex_index]:
                    # update path_list
                    path_list[adj_vertex_index] = alt_path
                    # update heap
                    hp.heappush(path_heap, (alt_path, adj_vertex_index))
                    parent_list[adj_vertex_index] = current_vertex_index
                    color[adj_vertex_index] = GRAY

    return path_list


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices_num = int(_input[0])
    init_vertices_table = list(map(lambda x: x.split(), _input[1:]))
    # assert len(init_vertices_table) == vertices_num

    parent_list, path_list = [-1] * vertices_num, [D_MAX] * vertices_num
    color = [WHITE] * vertices_num
    init_adj_matrix = tuple(dict() for _ in range(vertices_num))
    adj_matrix = generate_adj_matrix(init_vertices_table)
    ans = dijkstra_path()
    for i, v in enumerate(ans):
        print(i, v)

Python: # coding: utf-8
import queue
nodelist={}
n=int(input())
dist={}
used={}
for i in range(n):
    line=list(map(int,input().split()))
    nodelist[line[0]]=[]
    dist[line[0]]=99999999
    used[line[0]]=False
    j=2
    while True:
        try:
            nodelist[line[0]].append((line[j],line[j+1]))
            j+=2
        except:
            break
q=queue.PriorityQueue()
dist[0]=0
for node in nodelist.keys():
    q.put((dist[node],node))

while not q.empty():
    node=q.get()
    if used[node[1]]:
        continue
    else:
        used[node[1]]=True
    for edge in nodelist[node[1]]:
        if dist[edge[0]]>dist[node[1]]+edge[1]:
            dist[edge[0]]=dist[node[1]]+edge[1]
            q.put((dist[edge[0]],edge[0]))

for d in dist.items():
    print(*d)