Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
)

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

Python: 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)


    for i in range(n):
        print('{0} {1}'.format(i, d[i]))

Python: def shortest_path(V,uvc,start=0):
    distances = [INF]*V
    distances[start] = 0
    parents = list(range(V))

    for _ in range(V):
        modified = False
        for src,dst,cost in uvc:
            if distances[dst] > distances[src] + cost:
                distances[dst] = distances[src] + cost
                parents[dst] = src
                modified = True
        if modified == False:
            return distances,parents
    return None,None
import sys
INF = float("inf")
N = int(sys.stdin.readline())
G = tuple(tuple(map(int,sys.stdin.readline().rstrip().split()))[2:] for _ in range(N))
uvc = []
for i in range(N):
    for j in range(0,len(G[i]),2):
        uvc.append([i,G[i][j],G[i][j+1]])  
a,_ = shortest_path(N,uvc,0)
for i,v in enumerate(a):
    print(i,v)

Python: def Single_Source_Shortest_Path(adj_mat, cost, parent):
    N = len(cost)
    color = ["W" for n in range(N)]
    parent[0] = -1
    cost[0] = 0

    while True:
        mincost = 1000000

        for i in range(N):
            if color[i] != "B" and cost[i] < mincost:
                u = i
                mincost = cost[u]

        if mincost == 1000000:
            break

        color[u] = "B"

        for v in range(N):
            if color[v] != "B" and adj_mat[u][v] >= 0:
                if cost[v] > cost[u] + adj_mat[u][v]:
                    cost[v] = cost[u] + adj_mat[u][v]
                    parent[v] = u
                    color[v] = "G"

def Main():
    N = int(input())
    cost = [1000000 for n in range(N)]
    color = ["W" for n in range(N)]
    adj_mat = [[ -1 for n in range(N)] for n in range(N)]
    parent = [-1 for n in range(N)]

    for n in range(N):
        u, K, *p = map(int, input().split())

        for k in range(K):
            v, c = p[2*k], p[2*k + 1]
            adj_mat[u][v] = c

    Single_Source_Shortest_Path(adj_mat, cost, parent)

    for i in range(N):
        print("{} {}".format(i, cost[i]))

Main()

Python: N = 100
WHITE = 0
GRAY = 1
BLACK = 2
INF = float('inf')
M = None
d = [INF for _ in range(N)]
p = [0 for _ in range(N)]
color = [WHITE for _ in range(N)]
n = 0


def main():
    global n, M

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

    for i in range(n):
        _, k, *v_s = map(int, input().split(' '))
        for j in range(k):
            c_i = 2*j + 1
            v = v_s[2*j]
            M[i][v] = v_s[c_i]

    dijkstra(0)

    for i in range(n):
        print('{} {}'.format(i, d[i]))


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

    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


if __name__ == '__main__':
    main()