Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

Python: n = int(input())
global S, Q, l
S = [0]
Q = [0]
l = [1000000 for _ in range(n)]
l[0] = 0
graph = [[-1 for _ in range(n)] for _ in range(n)]
def input_graph(n):
  for _ in range(n):
    node_id, k, *v_list = list(map(int, input().split()))
    for j in range(k):
      ad_node, w = v_list[2*j], v_list[2*j+1]
      graph[node_id][ad_node] = w 


def dijkstra():
  while Q:
    u = float('inf') #10000000
    u_c = float('inf') #10000000
    for i in range(n):
      if i in Q and u_c > l[i]:
        u = i
        u_c = l[i]
    #print(l, u, S, Q)
    for i in range(n):
      v = i 
      if v not in S and graph[u][v] != -1:
        S.append(v)
        Q.append(v)
        l[v] = l[u] + graph[u][v]
      if (v in Q) and (l[v] > l[u] + graph[u][v]) and graph[u][v] != -1:
        l[v] = l[u] + graph[u][v]
    Q.remove(u)


if __name__ == "__main__":
  input_graph(n)
  dijkstra()
  for i, c in enumerate(l):
    print(i, c)

Python: 
def dijkstra():
    global n, color, M, d, p

    min_value = 1000000
    d[0] = 0
    color[0] = 'GRAY'

    while True:
        min_value = 1000000
        u = -1

        for i in range(n):
            if min_value > d[i] and color[i] != 'BLACK':
                u = i
                min_value = d[i]

        if u == -1:
            break

        color[u] = 'BLACK'

        for v in range(n):
            if color[v] != 'BLACK' and M[u][v] != 1000000:
                if d[v] > d[u] + M[u][v]:
                    d[v] = d[u] + M[u][v]
                    color[v] = 'GRAY'

    for i in range(n):
        if d[i] == 1000000:
            d[i] = -1

        print('{} {}'.format(i, d[i]))


n = int(input())

color = ['WHITE'] * n
M = [[1000000 for i in range(n)] for j in range(n)]
d = [1000000] * n  # 重みが最小の辺の重み
p = [-1] * n  # MSTにおけるp[v]の親（どこから来たか？？）

for i in range(n):
    _ = list(map(int, input().split()))
    u = _[0]
    degree = _[1]

    for j in range(degree):
        v = _[j*2+2]
        w = _[j*2+3]
        M[u][v] = w
# print(M)

dijkstra()

Python: def dijkstra(n):
    inf = 10 ** 6 + 1
    dist = [0] + [inf] * (n - 1)
    visited = [False] * n

    while not all(visited):
        dmin = inf
        for i, (d, v) in enumerate(zip(dist, visited)):
            if dmin > d and not v:
                dmin, u = d, i
        visited[u] = True
        for (v, c) in edge[u]:
            if dist[v] > dist[u] + c:
                dist[v] = dist[u] + c
    return dist

n = int(input())
edge = [[]] * n
for _ in range(n):
    l = list(map(int, input().split()))
    edge[l[0]] = (e for e in zip(l[2::2], l[3::2]))
for i, c in enumerate(dijkstra(n)):
    print(i, c)

Python: n = int(input())
G = [[] for i in range(n)]
for ni in range(n):
    u, k, *tmp = [int(i) for i in input().split()]
    for ki in range(k):
        G[ni].append(tmp[:2])
        del tmp[:2]

INF = 100*100000
D = [INF for i in range(n)]
D[0] = 0
C = [0 for i in range(n)]
while 0 in C:
    U = [INF if C[i] == 1 else D[i] for i in range(n)]
    u = U.index(min(U))

    for i in range(len(G[u])):
        v = G[u][i][0]
        if D[u] + G[u][i][1] < D[v]:
            D[v] = D[u] + G[u][i][1]
    C[u] = 1

for ni in range(n):
    print(ni, D[ni])

Python: import sys
import heapq
n = int(input())
V = [[int(i) for i in input().split()] for _ in range(n)]
dis = [sys.maxsize for _ in range(n)]
dis[0] = 0
h = []
for i in range(n):
    heapq.heappush(h,(dis[i],i))
while(len(h)>0):
    node = heapq.heappop(h)
    tmp = node[1]
    for i in range(V[tmp][1]):
        ind = V[tmp][2*i+2]
        cos = V[tmp][2*i+3]
        if cos + dis[tmp] < dis[ind]:
            dis[ind] = cos + dis[tmp]
            heapq.heappush(h,(dis[ind],ind))
for i,j in enumerate(dis):
    print(i,j)

Python: import heapq


def dijkstra(start_v, G):
    n = len(G)
    dist = [0 if i == start_v else float("inf") for i in range(n)]

    que = []
    heapq.heappush(que, (0, start_v))

    while que:
        cur_d, cur_v = heapq.heappop(que)
        if dist[cur_v] < cur_d:
            continue
        for adj in G[cur_v]:
            nxt_v, cost = adj
            if dist[cur_v] + cost < dist[nxt_v]:
                dist[nxt_v] = dist[cur_v] + cost
                heapq.heappush(que, (dist[nxt_v], nxt_v))

    return dist


def main():
    n = int(input())
    g = [[] for _ in range(n)]

    for i in range(n):
        data = [int(x) for x in input().split()]
        u, k = data[0], data[1]
        vc = data[2:]
        for j in range(k):
            v, c = vc[2 * j], vc[2 * j + 1]
            g[u].append((v, c))

    dist = dijkstra(0, g)

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


main()