Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

Python: n = int(input())
data = [list(map(int, input().split())) for _ in range(n)]
INF = 10000000000000000000
M = [[-1]*n for _ in range(n)]
for i in data:
    for j in range(i[1]):
        M[i[0]][i[2+j*2]] = i[3+j*2]
color = ['White']*n
d = [INF]*n
p = [None]*n

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

while True:
    minct = INF
    for i in range(n):
        if color[i] != 'Black' and d[i] < minct:
            minct = d[i]
            u = i
    if minct == INF:
        break
    color[u] = 'Black'
    for j in range(n):
        if color[j] != 'Black' and M[u][j] != -1:
            if d[u] + M[u][j] < d[j]:
                d[j] = d[u] + M[u][j]
                p[j] = u
                color[j] = 'Gray'
for i in range(n):
    print('{} {}'.format(i, d[i]))

Python: #coding:utf-8

inf = 1000000
n = int(input())
M = [[inf for i in range(n)] for j in range(n)]

for i in range(n):
    data = list(map(int,input().split()))
    u = data[0]
    k = data[1]
    for j in range(0,2*k,2):
        v, w = data[j+2], data[j+3]
        M[u][v] = w

def dijkstra(s):
    color = ["white" for i in range(n)]
    d = [inf for i in range(n)]
    p = [-1 for i in range(n)]
    d[s] = 0
    while True:
        mincost = inf
        for i in range(n):
            if color[i] != "black" and d[i] < mincost:
                mincost = d[i]
                u = i
        if mincost == inf:
            break
        color[u] = "black"

        for v in range(n):
            if color[v] != "black" and M[u][v] != inf:
                if d[u] + M[u][v] < d[v]:
                    d[v] = d[u] + M[u][v]
                    p[v] = u
                    color[v] = "gray"
    return d

dList = dijkstra(0)
for i, d in enumerate(dList):
    print(i,d)

Python: import sys
readline = sys.stdin.readline
write = sys.stdout.write

N = int(readline())

G = [None]*N
W = 0
for i in range(N):
    j, k, *V = map(int, readline().split())
    G[i] = [(v, c) for v, c in zip(V[::2], V[1::2])]
    if V:
        W = max(W, max(V[1::2]))

def dial(N, G, W, s):
    B = [-1]*(N*W + 1)
    L = [-1]*(N*W + 1)
    *prv, = range(-1, N-1)
    *nxt, = range(1, N+1)
    nxt[-1] = -1
    prv[s+1] = s-1
    nxt[s-1] = (s+1 if s < N-1 else -1)
    prv[s] = nxt[s] = -1
    B[0] = L[0] = s
    B[N*W] = +(s == 0)
    L[N*W] = (N-1 if s < N-1 else N-2)

    dist = [N*W] * N
    dist[s] = 0
    for w in range(N*W):
        v = B[w]
        while v != -1:
            for x, c in G[v]:
                e = w + c
                if e < dist[x]:
                    d = dist[x]
                    dist[x] = e

                    p = prv[x]; n = nxt[x]
                    if p != -1:
                        nxt[p] = n
                    else:
                        B[d] = n
                    if n != -1:
                        prv[n] = p
                    else:
                        L[d] = p

                    l = L[e]
                    if l != -1:
                        nxt[l] = x
                    else:
                        B[e] = x
                    prv[x] = l; nxt[x] = -1
                    L[e] = x
            v = nxt[v]
    return dist
dist = dial(N, G, W, 0)
ans = []
for i in range(N):
    ans.append("%d %d\n" % (i, dist[i]))
sys.stdout.writelines(ans)

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)