Go: package main

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

const (
	white int = iota
	gray
	black
)

type node struct {
	id     int
	parent int
	edge   []int
	weight []int
	color  int
}

type graph struct {
	nodes    []node
	distance []int
}

var infty = 1 << 32
var null = -1

func constructgraph() *graph {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n := nextInt(sc)

	g := &graph{make([]node, n), make([]int, n)}

	for i := 0; i < n; i++ {
		id := nextInt(sc)
		edges := nextInt(sc)
		n := node{}
		n.id = id
		n.edge = make([]int, edges)
		n.weight = make([]int, edges)
		n.color = white
		for j := 0; j < edges; j++ {
			to := nextInt(sc)
			w := nextInt(sc)
			n.edge[j] = to
			n.weight[j] = w
		}
		g.nodes[id] = n
	}
	return g
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func (g *graph) preparedijkstra(s int) {
	for i := 0; i < len(g.nodes); i++ {
		g.nodes[i].color = white
		g.nodes[i].parent = null
		g.distance[i] = infty
	}
	g.distance[s] = 0
}

func (g *graph) dijkstra(s int) []int {
	g.preparedijkstra(s)

	for {
		var u int
		mincost := infty
		for i, d := range g.distance {
			if g.nodes[i].color != black && mincost > d {
				mincost = d
				u = i
			}
		}

		if mincost == infty {
			break
		}

		g.nodes[u].color = black

		for i, e := range g.nodes[u].edge {
			if g.nodes[e].color != black {
				if g.distance[e] > g.distance[u]+g.nodes[u].weight[i] {
					g.distance[e] = g.distance[u] + g.nodes[u].weight[i]
					g.nodes[e].parent = u
					g.nodes[e].color = gray
				}
			}
		}
	}
	return g.distance
}

func printShortestPath(d []int) {
	for i, v := range d {
		fmt.Printf("%d %d\n", i, v)
	}
}

func main() {
	g := constructgraph()
	d := g.dijkstra(0)
	printShortestPath(d)
}

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


def generate_adj_table(v_table):
    for each in v_table:
        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_table[v_index][pair[0]] = pair[1]

    return init_adj_table


def dijkstra_path_heap():
    # path search init
    distance[init_vertex] = 0
    path_heap = []
    # heapq: rank by tuple[0], at here it's d[u]
    hp.heappush(path_heap, (0, init_vertex))

    while path_heap:
        current = hp.heappop(path_heap)[1]

        color[current] = BLACK

        for adj, cost in adj_table[current].items():
            if color[adj] is not BLACK:
                # alt: d[u] + w[u,v]
                alt_path = distance[current] + cost
                if alt_path < distance[adj]:
                    # update path_list
                    distance[adj] = alt_path
                    # update heap
                    hp.heappush(path_heap, (alt_path, adj))
                    color[adj] = GRAY
                    parents[adj] = current

    return distance


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

    distance = [float('inf')] * vertices
    parents = [-1] * vertices
    color = [WHITE] * vertices
    init_adj_table = tuple(dict() for _ in range(vertices))
    init_vertex = 0

    adj_table = generate_adj_table(v_info)
    ans = dijkstra_path_heap()
    for i, v in enumerate(ans):
        print(i, v)

Python: rootList = [-1 for i in range(n)]
parent = [0 for i in range(n)]
lenList = [0 for i in range(n)]

def getRoot(x):
    r = rootList[x]
    if r < 0:
        rootList[x] = x
    elif r != x:
        rootList[x] = getRoot(r)
    return rootList[x]


edgeList.sort(key=lambda x: x[0])
flag = True
while flag:
    flag = False
    for e in edgeList:
        if e[2] == 0:
            continue
        x = getRoot(e[1])
        y = getRoot(e[2])
        if x == 0 != y:
            parent[e[2]] = e[1]
            lenList[e[2]] += lenList[e[1]] + e[0]
            rootList[y] = 0
            flag = True
            break

for i, j in zip(range(n), lenList):
    print(i, j)

Python: #!/usr/bin/env python
from __future__ import division, print_function
from sys import stdin, maxint


def main():
    num = int(stdin.readline())

    L = []
    for _ in xrange(num):
        L.append([int(s) for s in stdin.readline().split()])

    weight = [maxint] * num
    index = 0
    rearch = {0}
    total_c = 0

    while maxint not in rearch:
        min_v = min_c = maxint
        Li = L[index]
        for i in xrange(Li[1]):
            v = Li[i*2+2]
            if v in rearch:
                continue
            c = Li[i*2+3]
            weight[v] = min(weight[v], c + total_c)
            if min_c > c:
                min_c = c
                min_v = v
        index = min_v
        rearch.add(min_v)
        total_c += min_c

    weight[0] = 0
    for i, d in enumerate(weight):
        print(i, d)


main()

Python: INFINITY = 10 ** 10
WHITE = 0
GRAY = 1
BLACK = 2


n = int(input())
M = [[INFINITY] * n for _ in range(n)]

for _ in range(n):
    u, k, *list_num = map(int, input().split())

    for i in range(0, k * 2, 2):
        M[u][list_num[i]] = list_num[i + 1]

d = [INFINITY] * n

def dijkstra():
    color = [WHITE] * n
    p = [None] * n

    d[0] = 0
    p[0] = -1

    while True:
        cost_min = INFINITY
        for i in range(n):
            if color[i] != BLACK and d[i] < cost_min:
                cost_min = d[i]
                top_now = i

        if cost_min == INFINITY:
            break
    
        color[top_now] = BLACK

        for v in range(n):
            if color[v] == BLACK or M[top_now][v] == INFINITY:
                continue

            cost_now = d[top_now] + M[top_now][v]
            if cost_now < d[v]:
                d[v] = cost_now
                p[v] = top_now
                color[v] = GRAY


dijkstra()

for i, cost in enumerate(d):
    print(i, cost)

Python: n = int(input())
C = [[] for _ in range(n)]
for _ in range(n):
    tmp = list(map(int,input().split()))
    for i in range(1,tmp[1]+1):
        C[tmp[0]].append(tuple(tmp[2*i:2*i+2]))


def dijkstra(start = 0):
    INF = 100000000
    d = [INF]*n
    visited = [False]*n

    d[start] = 0
    visited[start] = True
    S = {start}

    while 1:
        for s in S:
            for adj_weight in C[s]:
                if visited[adj_weight[0]] == False:
                    d[adj_weight[0]] = min(d[s] + adj_weight[1],d[adj_weight[0]])
        
        min_d = INF
        min_node = -1
        for i in range(n):
            if visited[i] == False and d[i] < min_d:
                min_d = d[i]
                min_node = i
        if min_node == -1:
            break
        else:
            visited[min_node] = True
            S.add(min_node)
    return d

ans = dijkstra()
for i in range(n):
    print("{} {}".format(i,ans[i]))

Python: def relax(u, v, w):
    if D[u] + w < D[v]:
        D[v] = D[u] + w
        P[v] = u

INF = float('inf')
N = int(input())
D = [INF for i in range(N)]
P = [None for i in range(N)]
C = ['w' for i in range(N)]
D[0] = 0

G = [[INF for j in range(N)] for i in range(N)]
for i in range(N):
    x = list(map(int, input().split()))
    g = x[2:]
    for j, n in enumerate(g):
        if j % 2 == 0:
            G[i][n] = g[j + 1]


while True:
    mincost = INF
    u = -1
    for i in range(N):
        if C[i] != 'b' and D[i] < mincost:
            mincost = D[i]
            u = i
    if u == -1:
        break
    C[u] = 'b'
    for v, w in enumerate(G[u]):
        if w != INF and C[v] != 'b':
            relax(u, v, w)
            C[v] = 'g'

for i, d in enumerate(D):
    print('{0} {1}'.format(i, d))