Go: package main

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

const (
	MAX_N      = 100
	MAX_WEIGHT = 100000
)

type Edge struct {
	start  int
	end    int
	weight int
}

type ShortestInfo struct {
	edges    []Edge
	shortest int
}

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

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	shortestList := make([]ShortestInfo, n)
	for i := 1; i < n; i++ {
		shortestList[i] = ShortestInfo{edges: []Edge{}, shortest: MAX_N*MAX_WEIGHT + 1}
	}

	adjacentMatrix, err := createAdjacentMatrix(n, sc)
	if err != nil {
		panic(err)
	}

	sssp([]int{1}, shortestList, adjacentMatrix)
	for _, v := range shortestList {
		fmt.Printf("%d %d\n", v.getEnd()-1, v.shortest)
	}
}

func (si ShortestInfo) getEnd() int {
	if len(si.edges) == 0 {
		return 1
	} else {
		return si.edges[len(si.edges)-1].end
	}
}

func createAdjacentMatrix(n int, sc *bufio.Scanner) ([][]int, error) {
	adjacentMatrix := make([][]int, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		adjacentMatrix[id] = make([]int, n)
		for j := 0; j < n; j++ {
			adjacentMatrix[id][j] = -1
		}
		vertexNum, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		for j := 0; j < vertexNum; j++ {
			v, err := nextInt(sc)
			if err != nil {
				return nil, err
			}
			c, err := nextInt(sc)
			if err != nil {
				return nil, err
			}
			adjacentMatrix[id][v] = c
		}
	}
	return adjacentMatrix, nil
}

func sssp(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]int) {
	for len(nodeStack) > 0 {
		currentNode := nodeStack[0]
		nodeStack = nodeStack[1:]
		currentShortest := getShortest(currentNode, shortestList)
		adjacents := findAdjacents(currentNode, adjacentMatrix)
		for i := 0; i < len(adjacents); i++ {
			adj := adjacents[i]
			if currentShortest.shortest+adj.weight < getShortest(adj.end, shortestList).shortest {
				setShortest(adj.end, adj, currentShortest, shortestList)
				nodeStack = append(nodeStack, adj.end)
			}
		}
	}
}

func getShortest(node int, shortestList []ShortestInfo) ShortestInfo {
	return shortestList[node-1]
}

func setShortest(node int, edge Edge, currentShortest ShortestInfo, shortestList []ShortestInfo) {
	newEdges := make([]Edge, len(currentShortest.edges)+1)
	for i := 0; i < len(newEdges)-1; i++ {
		newEdges[i] = currentShortest.edges[i]
	}
	newEdges[len(newEdges)-1] = edge
	shortestInfo := ShortestInfo{edges: newEdges, shortest: currentShortest.shortest + edge.weight}
	shortestList[node-1] = shortestInfo
}

func findAdjacents(currentNode int, adjacentMatrix [][]int) []Edge {
	adjacents := adjacentMatrix[currentNode-1]
	edges := []Edge{}
	for i, v := range adjacents {
		if v > 0 {
			edges = append(edges, Edge{start: currentNode, end: i + 1, weight: v})
		}
	}
	return edges
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

Python: def dijkstra():
    d[0] = 0
    color[0] = GRAY

    while True:
        minv = INF
        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 i in range(N):
            if color[i] != BLACK and M[u][i] != INF:
                if d[i] > d[u] + M[u][i]:
                    d[i] = d[u] + M[u][i]
                    color[i] = GRAY

INF = 10 ** 18
WHITH = 0
GRAY = 1
BLACK = 2
N = int(input())
M = [[INF for _ in range(N)] for _ in range(N)]
d = [INF] * N
color = [WHITH] * N

for i in range(N):
    lst = list(map(int, input().split()))
    for j in range(lst[1]):
        M[lst[0]][lst[2 + (j * 2)]] = lst[3 + (j * 2)]

dijkstra()
for i in range(N):
    v = d[i]
    if v == INF:
        v = -1
    print(i, v)

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# FileName: 	single_source_shortest_path
# CreatedDate:  2020-06-08 21:54:58 +0900
# LastModified: 2020-06-08 22:28:47 +0900
#


import os
import sys
from collections import deque
#import numpy as np
#import pandas as pd


def main():
    n = int(input())
    graph = [[] for _ in range(n)]
    for _ in range(n):
        line = list(map(int,input().split()))
        u,k = line[0],line[1]
        path = line[2:]
        for i in range(0,2*k,2):
            graph[u].append([path[i+1],path[i]])
    
#    print(graph)
    s=0
    distance=[-1]*n
    Q = deque([s])
    distance[0]=0
    

    while Q:
        u = Q.popleft()
        for dis,v in graph[u]:
            if distance[v]==-1:
                distance[v]=distance[u]+dis
                Q.append(v)

            if distance[v]>distance[u]+dis:
                distance[v]=distance[u]+dis
                Q.append(v)
            


    for i,dis in enumerate(distance):
        print(i,dis)


if __name__ == "__main__":
    main()

Python: INF = 100000 * 100

def dijkstra(s: int) -> None:
	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] != None:
				if d[u] + M[u][v] < d[v]:
					d[v] = d[u] + M[u][v]
					pi[v] = u
					color[v] = "GRAY"


if __name__ == "__main__":
	n = int(input())
	G = []
	M = [[None for _ in range(n)] for _ in range(n)]
	color = ["WHITE" for _ in range(n)]
	d = [INF for _ in range(n)]
	pi = [None for _ in range(n)]

	for _ in range(n):
		l = list(map(int, input().split()))
		u = l[0]
		k = l[1]
		for i in range(k):
			v = l[2 * (i + 1)]
			c = l[2 * (i + 1) + 1]
			M[u][v] = c
	dijkstra(0)
	for v in range(n):
		print(f"{v} {d[v]}")

Python: import sys

def dijkstra(v_count: int, edges: list, start: int,
             *, adj_matrix: bool = False, unreachable=float("inf")) -> list:
    """ ダイクストラ法
    :param v_count: 頂点数
    :param edges: 辺のリスト(隣接リストor隣接行列)
    :param start: スタートする頂点
    :param adj_matrix: edgesに渡したリストが隣接行列ならTrue
    :param unreachable: 到達不能を表すコスト値
                        隣接行列の辺の有無の判定および返すリストの初期値に使用
    """
    from heapq import heappush, heappop

    vertices = [unreachable] * v_count
    vertices[start] = 0
    q, rem = [(0, start)], v_count - 1

    while q and rem:
        cost, v = heappop(q)
        if vertices[v] < cost:
            continue
        rem -= 1

        dests = (filter(lambda x: x[1] != unreachable, enumerate(edges[v]))
                 if adj_matrix else edges[v])

        for dest, _cost in dests:
            newcost = cost + _cost
            if vertices[dest] > newcost:
                vertices[dest] = newcost
                heappush(q, (newcost, dest))

    return vertices

n = int(input())
inf = float("inf")
edges = [[inf]*n for _ in [0]*n]
for a in (tuple(map(int, l.split())) for l in sys.stdin):
    _from = a[0]
    for to, cost in zip(a[2::2], a[3::2]):
        edges[_from][to] = cost
vertices = dijkstra(n, edges, 0, adj_matrix=True)
for i, n in enumerate(vertices):
    print(i, n)