Go: package main

import (
	"fmt"
	"os"
	"bufio"
	"strings"
	"strconv"
)
var MAX = 1000000
type Vertex struct{
	Value int
	Routes map[int]int
	Done bool
}
func NewVertex(value int) *Vertex{
	routes := make(map[int]int)
	// for i, _ := range routes {
	// 	routes[i] = MAX
	// }
	return &Vertex{ value, routes, false }
}

func (v *Vertex) SetRoute(key, weight int) {
	v.Routes[key] = weight
}

type Path struct {
	Key int
	Weight int
}

var count = 0
func ShortestRoutes(list []*Vertex) []int {
	// create result table
	result  := make([]int, len(list))
	// fmt.Println(result)
	for i, _ := range result {
		result[i] = MAX
	}

	queue := make([]Path, 0)
	queue = append(queue, Path{0, 0})
	result[0] = 0

	for len(queue) != 0 {
		count++
		path := queue[0]
		queue = queue[1:]
		for key, weight := range list[path.Key].Routes {
			// fmt.Println(list[path.Key].Routes)
			// set to result
			// fmt.Printf("Path(%d, %d) ? result[%d] => %d, wieght: %d\n", path.Key, path.Weight, key, result[key], weight)
			if path.Weight + weight < result[key] {
				result[key] = path.Weight + weight 
				queue = append(queue, Path{key, result[key]})
			// } else if !list[key].Done {
			// 	queue = append(queue, Path{key, result[key]})
			}
		}
		list[path.Key].Done = true
	}
	return result
}
func main() {
	var n int
	fmt.Scanf("%d", &n)
	list := make([]*Vertex, n)
	scanner := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		scanner.Scan()
		elements := strings.Split(scanner.Text(), " ")
		value, _ := strconv.Atoi(elements[0])
		list[i] = NewVertex(value)
		for j := 2; j < len(elements); j += 2 {
			key, _    := strconv.Atoi(elements[j])
			weight, _ := strconv.Atoi(elements[j + 1])
			list[i].SetRoute(key, weight)
		}
	}

	result := ShortestRoutes(list)
	for i := 0; i < len(result); i++ {
		fmt.Printf("%d %d\n", i, result[i]);
	}
	// fmt.Printf("count: %d\n", count)
}

Python: import sys
readline = sys.stdin.readline
from heapq import heapify, heappush, heappop
INF = float("inf")
def MAIN():
    n = int(input())
    adj = [[]] * n
    for _ in range(0, n):
        U = list(map(int, input().split()))
        adj[U[0]] = zip(U[2::2], U[3::2])
    def dijkstra():
        d = [INF] * n
        d[0] = 0
        hq = [(0, 0)]
        while hq:
            u = heappop(hq)[1]
            for v, c in adj[u]:
                alt = d[u] + c
                if d[v] > alt:
                    d[v] = alt
                    heappush(hq, (alt, v))
        print("\n".join(f"{i} {c}" for i, c in enumerate(d)))
    dijkstra()
MAIN()

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

N = int(input())
INF = float("inf")
costs = {n: INF for n in range(N)}
costs[0] = 0
graph = [{} for _ in range(N)]

unsearched = list(range(N))

for n in range(N):
    inp = tuple(map(int, input().split()))
    assert n == inp[0]
    for i in range(inp[1]):
        graph[n][inp[2*i+2]] = inp[2*i+3]

heap = [[0, 0]]
while len(unsearched) > 1:
    if len(heap):
        _, p = heappop(heap)
        unsearched.remove(p)
    heap = []
    for g in graph[p].keys():
        if g in unsearched:
            new_cost = costs[p] + graph[p][g]
            if new_cost < costs[g]:
                costs[g] = new_cost
            heappush(heap, [new_cost, g])
        else:
            pass

for n in range(N):
    print("{} {}".format(n, costs[n]))

Python: import heapq

class ShortestPath:
    def __init__(self, V, E, start, INF = float('inf')):
        self.V = V
        self.E = E 
        self.dijkstra(start, INF)

    def dijkstra(self, start, INF):
        que = list()
        self.distance = [INF] * self.V
        self.prev = [-1] * self.V
        self.distance[start] = 0
        heapq.heappush(que, (0, start))

        while len(que) > 0:
            dist, fr = heapq.heappop(que)
            if self.distance[fr] < dist:
                continue
            for to, cost in self.E[fr]:
                if self.distance[fr] + cost < self.distance[to]:
                    self.distance[to] = self.distance[fr] + cost
                    heapq.heappush(que, (self.distance[to], to))
                    self.prev[to] = fr 


V = int(input())
edge = [[] for _ in range(V)]
for _ in range(V):
    u, _, *e = map(int, input().split())
    for t, d in zip(e[::2], e[1::2]):
        edge[u].append((t, d))

sp = ShortestPath(V, edge, 0)
for i, d in enumerate(sp.distance):
    print(i, d)

Python: import heapq


def dijkstra(n):
    inf=float("inf")
    color=["white" for _ in range(n)]
    D=[inf for _ in range(n)]
    P=[0 for _ in range(n)]
    M=[[] for _ in range(n)]

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

    D[0]=0
    P[0]=-1

    H=[(0,0)]
    heapq.heapify(H)

    while len(H)>=1:
        u=heapq.heappop(H)[1]
        if color[u]=="black":continue
        color[u]="black"

        V=[(i,j) for i,j in M[u] if color[i]!="black"]
        while len(V)!=0:
            for i,j in V:
                if D[u]+j<D[i]:
                    D[i]=D[u]+j
                    P[i]=u
                    color[i]="gray"
                    heapq.heappush(H,(D[i],i))
            break

    return D


for i,j in enumerate(dijkstra(int(input()))):
    print(i,j)

Python: import sys

f_i = sys.stdin

n = int(f_i.readline())

adj = [[]] * n
for x in f_i:
    x = list(map(int, x.split()))
    adj[x[0]] = (c_v for c_v in zip(x[3::2], x[2::2]))

import heapq

def dijkstra():
    PQ = [(0, 0)]
    isVisited = [False] * n
    distance = [999900001] * n

    distance[0] = 0
    
    while PQ:
        uc, u = heapq.heappop(PQ)

        if uc > distance[u]:
            continue

        isVisited[u] = True
        
        for vc, v in adj[u]:
            if isVisited[v] == True:
                continue
            
            t_cost = distance[u] + vc
            if t_cost < distance[v]:
                distance[v] = t_cost
                heapq.heappush(PQ, (t_cost, v))

    for v, d in enumerate(distance):
        print(v, d)


dijkstra()

Python: import sys
readline = sys.stdin.readline
from heapq import heapify, heappush, heappop
INF = float("inf")
def MAIN():
    n = int(input())
    adj = [[]] * n
    for _ in range(0, n):
        U = list(map(int, input().split()))
        adj[U[0]] = zip(U[2::2], U[3::2])
    def dijkstra():
        d = [0] + [INF] * (n - 1)
        hq = [(0, 0)]
        while hq:
            u = heappop(hq)[1]
            for v, c in adj[u]:
                alt = d[u] + c
                if d[v] > alt:
                    d[v] = alt
                    heappush(hq, (alt, v))
        print("\n".join(f"{i} {c}" for i, c in enumerate(d)))
    dijkstra()
MAIN()

Python: from sys import stdin
import heapq
INF = 1<<21
n = int(stdin.readline())
adj = [[]] * n
for u in range(0, n):
    U = list(map(int, stdin.readline().split()[2:]))
    adj[u] = [e for e in zip(U[0::2], U[1::2])]
def dijkstra():
    d = [0] + [INF] * (n - 1)
    hq = [(0, 0)]
    while hq:
        u = heapq.heappop(hq)[1]
        for v, c in adj[u]:
            alt = d[u] + c
            if d[v] > alt:
                d[v] = alt
                heapq.heappush(hq, (alt, v))
    for i, c in enumerate(d):
        print(i, c)
dijkstra()