Go: package main

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

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

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(" ".join(map(str, (i, c))) for i, c in enumerate(d)))
    dijkstra()
MAIN()

Python: import heapq as pq
inf = float("inf")
n = int(input())
M = [[inf for i in range(n)] for i in range(n)]
for i in range(n):
    L = list(map(int, input().split()))
    for j in range(L[1]):
        M[L[0]][L[2 * j + 2]] = L[2 * j + 3]


def dijkstra(s):
    color = [0] * n
    d = [inf] * n
    d[s] = 0
    H =[]
    pq.heappush(H, [0, s])

    while len(H) != 0:
        u2,u1 = pq.heappop(H)
        color[u1] = 1
        if d[u1] < u2:
            continue
        for v in range(n):
            if color[v] != 1 and M[u1][v] != inf:
                if d[u1] + M[u1][v] < d[v]:
                    d[v] = d[u1] + M[u1][v]
                    pq.heappush(H, [d[v], v])
    return d

d = dijkstra(0)
for i,v in enumerate(d):
 print("{} {}".format(i,v))

Python: #ALDS_1_12_C Single Source Shortest Path II
import sys
import heapq

n = int(input())
G = [[] for _ in range(n)]
for i in range(n):
    u, k, *vc = list(map(int, sys.stdin.readline().strip().split()))
    for j in range(k):
        G[u].append([vc[j * 2], vc[j * 2 + 1]])

p = [] * n
c = ['white'] * n
d = [] * n
heapq.heappush(d, (0, 0))  # (distance, node)

mindist = [float('inf')] * n
mindist[0] = 0

while d:
    now = heapq.heappop(d)[1]

    #  色識別はなくても実行可能だが、枝刈りのために実行
    if c[now] == 'black':
        continue
    c[now] = 'black'

    for i in G[now]:
        if mindist[now] + i[1] < mindist[i[0]]:
            mindist[i[0]] = mindist[now] + i[1]
            heapq.heappush(d, [mindist[i[0]], i[0]])

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

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(5e10 + 1)


def generate_adj_matrix(v_info):
    for each in v_info:
        v_index, v_adj_length, *v_adj_list = map(int, each)
        # assert len(v_adj_list) == v_adj_length * 2
        for pair in zip(v_adj_list[::2], v_adj_list[1::2]):
            init_adj_matrix[v_index][pair[0]] = pair[1]

    return init_adj_matrix


def dijkstra_path():
    # path search init
    path_list[init_vertex_index] = 0
    path_heap = []
    # heapq: rank by tuple[0], here ranked by d[u]
    hp.heappush(path_heap, (0, init_vertex_index))
    while len(path_heap) >= 1:
        current_vertex_index = hp.heappop(path_heap)[1]

        color[current_vertex_index] = BLACK

        current_vertex_index_info = adj_table[current_vertex_index]
        for adj_vertex_index in current_vertex_index_info.keys():
            current_adj_weight = current_vertex_index_info.get(adj_vertex_index)
            if color[adj_vertex_index] is not BLACK:
                # alt: 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 = 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))
    init_vertex_index = 0

    adj_table = generate_adj_matrix(init_vertices_table)
    ans = dijkstra_path()
    for i, v in enumerate(ans):
        print(i, v)

Python: from heapq import*
I=float("inf")
def m():
 n=int(input())
 A=[]
 for _ in[0]*n:
  e=list(map(int,input().split()))
  A+=[zip(e[2::2],e[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: from heapq import heappop,heappush
INF = float("inf")
white = 0; gray = 1; black =2

def dijkstra(s):
    # 頂点sをrootに設定
    dist[s] = 0 
    heappush(PQ,(0,s))
    color[s] = gray

    while PQ:
        #最短経路木に頂点(最短経路木とつながる最小コストの辺を持つ頂点)を追加
        mincost,u = heappop(PQ)
        color[u] = black
        if dist[u] < mincost: continue # 最短じゃなかったら無視

        # 追加した頂点uの隣接頂点についてsからの最小コストを更新
        for v,cost in adj[u]:
            if color[v] == black: continue # 確定済み
            if dist[v] > dist[u] + cost:
                dist[v] = dist[u] + cost
                heappush(PQ,(dist[v],v))
                color[v] = gray

if __name__ == "__main__":
    n = int(input())
    adj = [[] for _ in range(n)]
    for i in range(n):
        inp = [int(x) for x in input().split()]
        u = inp[0]
        for v,c in zip(inp[2::2],inp[3::2]): adj[u].append((v,c))
    color = [white]*n #各頂点の訪問状態 （white:未訪問 gray:暫定 black:確定）
    dist = [INF]*n # 始点sからの最小コスト
    PQ = []
    dijkstra(0)
    for i in range(n): print("{} {}".format(i,dist[i]))

Python: import heapq
def Dsa(n):
    inf = 10 ** 6 + 1
    dt = [0] + [inf] * (n - 1)
    q = [(0, 0)]
    while q:
        u = heapq.heappop(q)[1]
        for (v, c) in ed[u]:
            alt = dt[u] + c
            if dt[v] > alt:
                dt[v] = alt
                heapq.heappush(q, (alt, v))
    return dt
 
n = int(input())
ed = [[]] * n
for _ in range(n):
    l = list(map(int, input().split()))
    ed[l[0]] = (e for e in zip(l[2::2], l[3::2]))
for i, c in enumerate(Dsa(n)):
    print(i, c)