Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
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 = i
	pq[j].index = j
}
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
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

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

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

		out[u] = d
		visited[u] = struct{}{}
	}

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

Python: # -*- coding: utf-8 -*-
"""
Created on Sat Jul 14 19:11:44 2018

@author: maezawa
"""
infinity = 2*10**9

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

for j in range(n):
    ain = list(map(int, input().split()))
    u = ain[0]
    k = ain[1]
    for i in range(2,2+2*k,2):
        adj[u].append([ain[i],ain[i+1]])
    #print(*adj[u])

color = [0]*n
d = [infinity for _ in range(n)]
p = [0]*n
p[0] = -1
d[0] = 0

def dyk(s):
    cnt = 1
    cur = s
    candidates = set() # remaining nodes
    while True:
        for i, w in adj[cur]:
            if color[i] == 2:
                continue
            if d[i] > d[cur] + w:
                d[i] = d[cur] + w
                color[i] = 1
            candidates.add(i)
        min_d = infinity
        for j in candidates:
            if min_d > d[j]:
                min_node = j
                min_d = d[j]
        candidates.remove(min_node)
        p[min_node] = cur
        color[cur] = 2
        cur = min_node
        cnt += 1
        print(cur, d)
        print(candidates)
        if cnt == n:
            break
    return

dyk(0)
for i in range(n):
    print(i, d[i])

Python: import sys
import math

n = int(sys.stdin.readline())

Q = set()
out_edge = [set() for _ in range(n)]
weight = [[0] * n for _ in range(n)]

for _ in range(n):
    ll = list(map(int, sys.stdin.readline().split()))
    sn = ll[0]
    Q.add(sn)
    for j in range(ll[1]):
        en = ll[2+2*j]
        cn = ll[2+2*j+1]
        out_edge[sn].add(en)
        weight[sn][en] = cn

d = [0] + [math.inf for _ in range(n-1)]
prev = [None] * n

while len(Q)>0:
    minval = math.inf
    u = -1
    for q in Q:
        if minval > d[q]:
            minval = d[q]
            u = q
    if minval==math.inf:  break
    Q.remove(u)

    for v in out_edge[u]:
        if weight[u][v]>0:
            if d[v] > d[u] + weight[u][v]:
                d[v] = d[u] + weight[u][v]
                prev[v] = u

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

Python: from sys import stdin
INF = 1<<21
WHITE, GRAY, BLACK = 0, 1, 2
n = int(stdin.readline())
M = [[INF] * n for _ in range(n)]
for u in range(0, n):
    U = list(map(int, stdin.readline().split()[2:]))
    for j in range(0, len(U), 2):
        M[u][U[j]] = U[j + 1]
d = [INF] * n
d[0] = 0
color = [WHITE] * n
color[0] = GRAY
def dijkstra():
    global n
    while True:
        minv = INF
        u = -1
        for i in range(0, n):
            if minv > d[i] and color[i] != BLACK:
                u = i
                minv = d[i]
        if u == -1: break
        color[u] = BLACK
        for v in range(0, n):
            if color[v] != BLACK and M[u][v] != INF and d[v] > d[u] + M[u][v]:
                d[v] = d[u] + M[u][v]
                color[v] = GRAY
    for i in range(0, n):
        print(i, (-1 if d[i] == INF else d[i]))
dijkstra()

Python: 
n=int(input())
graph=[[0]*n for i in range(n)]


#graph[i][j]は、頂点iから頂点jへの枝の重みを表す(0は枝なし)
for loop in range(n):
    tmp_ope=list(map(int,input().split()))
    for j in range(1,tmp_ope[1]+1):
        graph[tmp_ope[0]][tmp_ope[2*j]]=tmp_ope[2*j+1]

#S[i]＝１の時、頂点iは走査済み
S=[0]*n
#d[i]はSに含まれる点のみを使って、頂点iにたどり着くときの最短パス
d=[999999]*n
d[0]=0

for loop in range(n):
    tmp_vertex=-1

    #tmp_vertexは走査済みでない点の中で、d[i]が最小となるインデックス
    for j in range(n):
        if(S[j]==0):
            if(tmp_vertex!=-1):
                if(d[j] < d[tmp_vertex]):
                    tmp_vertex=j
            else:
                tmp_vertex=j
    
    
    S[tmp_vertex]=1

    #dを更新
    for j in range(n):
        if(graph[tmp_vertex][j]!=0 and S[j]==0):
            d[j]=min([ d[j], d[tmp_vertex] + graph[tmp_vertex][j] ])

for i in range(n):
    print(f"{i} {d[i]}")

Python: def diikstraMethd(G, s):
    # ?????????
    n = len(G)
    # White:0 Gyay:1 Black:2
    color = [0 for _ in range(n)]
    d = [INF for _ in range(n)]
    p = [None for _ in range(n)]

    d[s] = 0

    while True:
        mincost = INF
        for i in range(n):
            if color[i] != 2 and d[i] < mincost:
                mincost = d[i]
                u = i

        if mincost == INF: break

        color[u] = 2

        for v in range(n):
            if color[v] != 2 and M[u][v] != INF:
                if d[u] + M[u][v] < d[v]:
                    d[v] = d[u] + M[u][v]
                    p[v] = u
                    color[u] = 1

    return d

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


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