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: import sys
input = sys.stdin.readline

INF = 100100

def dijkstra(M: list, u: int = 0) -> list:
    global N
    d = [INF] * N
    d[u] = 0
    visited = [False] * N
    while True:
        mincost = INF
        for i in range(N):
            if not visited[i] and d[i] < mincost:
                mincost = d[i]
                u = i
        if mincost == INF:
            return d
        visited[u] = True
        for v in range(N):
            if not visited[v]:
                if d[u] + M[u][v] < d[v] :
                    d[v] = d[u] + M[u][v]


def main():
    global N
    N = int(input())
    M = [[INF]*N for _ in range(N)]
    for _ in range(N):
        A = list(map(int, input().split()))
        u = A[0]
        k = A[1]
        for i in range(k):
            v = A[2+2*i]
            c = A[3+2*i]
            M[u][v] = c
    d = dijkstra(M)
    for i, di in enumerate(d):
        print(i, di)

if __name__ == '__main__': main()

Python: # -*- coding: utf-8 -*-

N = int(input())
INF = float("inf")
adj = [[INF]*N for _ in range(N)]

for n in range(N):
    inp = tuple(map(int, input().split()))
    assert n == inp[0]
    for i in range(inp[1]):
        adj[inp[0]][inp[2*i+2]] = inp[2*i+3]

not_MST = list(range(1, N))
MST = [0]
costs = {n:INF for n in range(N)}
costs[0] = 0

for n in range(1, N):
    if adj[0][n] < INF:
        costs[n] = adj[0][n]

m = 0

while len(not_MST):
    tmp_min = INF
    tmp_idx = -1
    
    for n in not_MST:
        if costs[m] + adj[m][n] < costs[n]:
            costs[n] = costs[m] + adj[m][n]
    
    for m in not_MST:
        if costs[m] < tmp_min:
            tmp_min = costs[m]
            tmp_idx = m
    
    MST.append(tmp_idx)
    not_MST.remove(tmp_idx)
    m = tmp_idx

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

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.remove(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: n = int(input())
edgeList = []

for i in range(n):
    a = list(map(int, input().split()))
    for j in range(a[1]):
        edgeList.append([a[2*j+3], i, a[2*j+2]])

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)

Python: from sys import stdin

INFTY = 1 << 21
WHITE = 0
GRAY = 1
BLACK = 2

n = int(stdin.readline())
M = [[INFTY for i in range(n)] for j in range(n)]

for u in range(n):
    U = list(map(int, stdin.readline().split()[2:]))
    for j in range(0, len(U), 2):
        M[u][U[j]] = U[j+1]

d = [INFTY for i in range(n)]
color = [WHITE for i in range(n)]

def dijkstra():
    global n
    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()