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())

adj = [[False 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

weights = [9900000] * n


def search(goal, path, weight):
    e = path[-1]
    if weight < weights[goal]:
        if e == goal:
            weights[goal] = weight
        else:
            for v, c in enumerate(adj[e]):
                if (v not in path) and (c is not False):
                    path.append(v)
                    weight += c
                    search(goal, path, weight)
                    weight -= c
                    path.pop()


for i in range(n):
    search(i, [0], 0)

for v, w in enumerate(weights):
    print(v, w)

Python: INFTY = 1 << 21
WHITE = 0
GRAY = 1
BLACK = 2
 
n = int(input())
M = [list(map(int, input().split())) for i in range(n)]
 
d = [INFTY for i in range(n)]
color = [WHITE for i in range(n)]
 
for i in range(n):
    u = int(input())
    k = int(input())
    for j in range(k):
        v = int(input())
        c = int(input())
        M[u][v] = c
        
def dijkstra():
    global M, d, color
    d[0] = 0
    color[0] = GRAY
    while(1):
        minv = INFTY
        u = -1
        for i in range(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(n):
            if (color[v] != BLACK and M[u][v] != INFTY):
                if (d[v] > d[u] + M[u][v]):
                    d[v] = d[u] + M[u][v]
                    color[v] = GRAY
    for i in range(n):
        print(i, (-1 if d[i] == INFTY else d[i]))
dijkstra()

Python: import sys
from collections import defaultdict


def main():
    n = int(input())
    lines = sys.stdin.readlines()
    vertex_weights = defaultdict(list)
    for i in range(n):
        u, k, *vtx_wght = map(int, lines[i].split())
        for v_i in range(k):
            vertex_weights[u].append((vtx_wght[2*v_i], vtx_wght[2*v_i+1]))

    dist_from_0 = {}
    vertices = [(0, 0)]
    while len(dist_from_0) != n:
        vertices.sort(key=lambda x: x[1], reverse=True)
        vtx, vtx_dist = vertices.pop()
        dist_from_0[vtx] = vtx_dist

        neighbor_vtx = vertex_weights[vtx]

        for n_vtx, n_dist in neighbor_vtx:
            if n_vtx not in dist_from_0.keys():
                vertices.append((n_vtx, vtx_dist + n_dist))

        [vertices.remove(x) for x in vertices[:] if x[0] in dist_from_0]


    answers = [None] * n
    sorted_dist = sorted(dist_from_0.items(), key=lambda x: x[0])
    for i in range(n):
        answers[i] = f"{sorted_dist[i][0]} {sorted_dist[i][1]}"
    [print(ans) for ans in answers]
    return


main()

Python: n=int(input())
d=[0]+[1e6]*n
c=[1]*n
M=[[-1]*n for _ in[0]*n]

for _ in[0]*n:
 data=list(map(int,input().split()))
 for i in range(data[1]):k=2*-~i;M[data[0]][data[k]]=data[k+1]

while 1:
 m,u=1e6,-1
 
 for i in range(n):
  if m>d[i]and c[i]:
      m,u=d[i],i
 if u<0:
     break
 c[u]=0
 
 for v in range(n):
  if c[v]and 1+M[u][v]and d[v]>d[u]+M[u][v]:
   d[v]=d[u]+M[u][v]
   
for i in range(n):
    print(i,d[i])

Python: n = int(input())
adj = [[float('inf')]*n for _ in range(n)]
for i in range(n):
    a = list(map(int, input().split()))
    for j,k in zip(a[2::2], a[3::2]):
        adj[i][j] = k
color = [0]*n
d = [float('inf')]*n
d[0] = 0

while 1:
    mincost = float('inf')
    for i in range(n):
        if color[i] != 1 and d[i] < mincost:
            mincost = d[i]
            u = i
    if mincost == float('inf'):
        break
        
    color[u] = 1
    
    for i in range(n):
        if color[i] != 1 and adj[u][i] != float('inf'):
            if d[u]+adj[u][i] < d[i]:
                d[i] = d[u] + adj[u][i]
                
for i in range(n):
    print(i, d[i])

Python: 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 ci[u][v] != inf:
                if d[u] + ci[u][v] < d[v]:
                    d[v] = d[u] + ci[u][v]
                    p[v] = u
                    color[v] = "gray"
    return d


inf = 10 ** 9
n = int(input())
ci = [[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]
        ci[u][v] = w

dList = dijkstra(0)

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