Go: // ダイクストラのアルゴリズム
package main

import (
	"bufio"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

type color int

const (
	white color = iota // 未訪問
	mst                // MSTとして確定
)

// 頂点
type node struct {
	num       int         // 頂点の番号
	weights   map[int]int // 重みMAP
	parent    *node       // MSTへの重み最小の親
	distFromS int         // 始点からの距離
	color     color
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	n := eGetInt(scanner)

	nodes := make([]*node, n)
	for i := 0; i < n; i++ {
		weights := eAtoi((strings.Fields(eGetline(scanner))))
		v := &node{weights[0], make(map[int]int, weights[1]), nil, math.MaxInt32, white}
		for j := 0; j < weights[1]; j++ {
			k := weights[j*2+2] // 相手の頂点名
			w := weights[j*2+3] // 重み
			v.weights[k] = w
		}
		nodes[i] = v
	}

	// 初回はnode[0]がMSTに入るように
	nodes[0].distFromS = 0

	for { // 全部チェックするまで

		// どの頂点を新たにMSTに取り込むか

		var minNode *node
		min := math.MaxInt32
		for _, v := range nodes {
			if v.color == mst {
				continue
			}
			if v.distFromS < min {
				min = v.distFromS
				minNode = v
			}
		}
		if minNode == nil {
			// すべて完了している.
			break
		}

		// MSTに追加する頂点決定
		minNode.color = mst

		// fmt.Printf(">[%v]\n", minNode)
		// MSTに属していない頂点それぞれについて,Startからの最小の重みの距離を更新
		for i, v := range nodes {
			if v.color == mst {
				continue
			}
			w, ok := minNode.weights[i]
			if !ok {
				// minNodeと接してない
				continue
			}

			if minNode.distFromS+w < v.distFromS {
				// minNode経由の距離がもっとも重みが少ないので親を変更
				v.distFromS = minNode.distFromS + w
				v.parent = minNode
				// fmt.Printf("[%v %v]\n", v, minNode)
			}
		}
		// fmt.Printf("<\n")
	}

	for i, v := range nodes {
		fmt.Printf("%d %d\n", i, v.distFromS)
	}
}

func eGetInt(scanner *bufio.Scanner) int {
	t := eAtoi(strings.Fields(eGetline(scanner)))
	return t[0]
}

func eGetline(p *bufio.Scanner) string {
	if !p.Scan() {
		if err := p.Err(); err != nil {
			log.Fatal(err.Error())
		}
		return ""
	}
	return p.Text()
}

func eAtoi(s []string) []int {
	ints := make([]int, len(s))
	var err error
	for i, e := range s {
		ints[i], err = strconv.Atoi(e)
		if err != nil {
			log.Fatal(err.Error())
		}
	}
	return ints
}

Python: n = int(input())
M = {}
for _ in range(n):
    u, k, *line = map(int, input().split())
    tmp = []
    for i in range(k):
        v, w = line[2*i:2*i+2]
        tmp.append((v, w))
    M[u] = tmp

INF = 10**10
WHITE = 0
GREY = 1
BLACK = 2
d = [INF] * n
color = [WHITE] * n
p = [-1] * n


def dijkstra():
    d[0] = 0
    p[0] = -1

    while True:
        mincost = INF
        for i in range(0, n):
            if color[i] != BLACK and d[i] < mincost:
                mincost = d[i]
                u = i

        if mincost == INF:
            break

        color[u] = BLACK

        for v, w in M[u]:
            if color[v] != BLACK:
                if d[u]+w < d[v]:
                    d[v] = d[u]+w
                    p[v] = u


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

Python: N = int(input())
color = ["w" for _ in range(N)]
d = [float("inf") for _ in range(N)]
p = [-1 for _ in range(N)]

# Make M
M = [[-1]*N for _ in range(N)]
for i in range(N):
    input_list = list(map(int, input().split()))
    ii = input_list.pop(0)
    k = input_list.pop(0)
    jj = 0
    while jj <= 2*k - 2:
        M[ii][input_list[jj]] = input_list[jj+1]
        jj += 2

d[0] = 0
while True:
    mincost = float("inf")
    for i in range(N):
        if color[i] != "b" and d[i] < mincost:
            mincost = d[i]
            u = i
    
    if mincost == float("inf"):
        break
    color[u] = "b"

    for v in range(N):
        if color[v] != "b" and M[u][v] != -1:
            if d[v] > M[u][v] + d[u]:
                d[v] = M[u][v] + d[u]
                p[v] = u
                
for i in range(N):
    print("{} {}".format(i, d[i]))

Python: INF = 1000000


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)

Python: n = int(input())

adj = [[100001 for j in range(n)] for i in range(n)]

for u in range(n):
    x = list(map(int, input().split()))
    for v, c in zip(x[2::2], x[3::2]):
        adj[u][v] = c

unvisited = {v for v in range(n)}

distance = [9900001] * n


def dijkstra(s):
    distance[s] = 0

    while True:
        mincost = 9900001
        for i in unvisited:
            if distance[i] < mincost:
                mincost = distance[i]
                u = i

        if mincost == 9900001:
            break

        unvisited.discard(u)

        for v in unvisited:
            weight_uv = adj[u][v]
            if weight_uv != 100001:
                t_d = distance[u] + weight_uv
                if t_d < distance[v]:
                    distance[v] = t_d



dijkstra(0)

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

Python: import sys
from heapq import *

MAX_INT= 10 ** 10

n = int(input())
adj_list = []

for _ in range(n):
  commands = sys.stdin.readline().split()
  lst = [ commands[i:i+2] for i in range(2, len(commands), 2)]
  adj_list.append(lst)

def dijkstra():
  # initialization
  visited = [False] * n
  dist_arr = [MAX_INT] * n
  pq = []
  prev = [None] * n

  # append 0 to pqs
  pq = [(0, 0)]
  dist_arr[0] = 0

  while len(pq) > 0:
    dist, idx = heappop(pq)
    visited[idx] = True

    # updating current values in dist
    for edge in adj_list[idx]:
      cur_idx, cur_dist = [ int(e) for e in edge]
      if visited[cur_idx]: continue

      new_dist = dist + cur_dist

      if new_dist < dist_arr[cur_idx]:
        dist_arr[cur_idx] = new_dist
        heappush(pq, (dist_arr[cur_idx], cur_idx))

  return dist_arr

distArr = dijkstra()
for i in range(n):
  print(i, distArr[i])

Python: inf = float('inf')
n = int(input())
g = []
for i in range(n):
    line = list(map(int, input().split()))
    k = line[1]
    c = [inf] * n
    for j in range(k):
        v = line[2 + 2 * j]
        c[v] = line[3 + 2 * j]
    g.append(c)

distance = [inf] * n
distance[0] = 0
visited = [False] * n
current = 0

while not all(visited):
    visited[current] = True
    min_i = 0
    min_d = inf
    for i in range(n):
        if not visited[i]:
            if distance[current] + g[current][i] < distance[i]:
                distance[i] = distance[current] + g[current][i]
            if distance[i] < min_d:
                min_i = i
                min_d = distance[i]
    current = min_i

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

Python: N = int(input())

E = [None] * N
for _ in range(N):
    u, k, *vs = map(int, input().split())
    E[u] = []
    for i in range(k):
        v, c = vs[i*2], vs[i*2+1]
        E[u].append((v, c))

vis = [False] * N
inf = 1e9
d = [inf] * N
d[0] = 0
for _ in range(N):
    nv, ni = inf, -1
    for i in range(N):
        if not vis[i] and d[i] < nv:
            nv, ni = d[i], i
    vis[ni] = True
    for v, c in E[ni]:
        d[v] = min(d[v], d[ni] + c)

for v in range(N):
    print(v, d[v])