TheAlgorithms-Python/graphs/Directed (Weighted) Graph

from collections import deque
import random as rand
import math as math

# the dfault weight is 1 if not assigend but all the implementation is weighted

class DirectedGraph:
	# enter True or False for this constructor
	def __init__(self):
		self.graph = {}

	# adding vertices and edges
	# note that self loops are not supported in undirected simpl graphs but it is in multigraphs
	def add_pair(self, u, v, w = 1):
		if self.graph.get(u):
			if self.graph[u].count([w,v]) == 0:
				self.graph[u].append([w, v])
		else:
			self.graph[u] = [[w, v]]
		if not self.graph.get(v):
			self.graph[v] = []
	def remove_pair(self, u, v):
		if self.graph.get(u):
			for _ in self.graph[u]:
				if _[1] == v:
					self.graph[u].remove(_)

	# if no destination is meant the defaut value is -1
	def dfs(self, s = -2, d = -1):
		if s == d:
			return []
		stack = []
		visited = []
		if s == -2:
			s = list(self.graph.keys())[0]
		stack.append(s)
		visited.append(s)
		ss = s

		while True:
			# check if there is any non isolated nodes
			if len(self.graph[s]) != 0:
				ss = s
				for __ in self.graph[s]:
					if visited.count(__[1]) < 1:
						if __[1] == d:
							visited.append(d)
							return visited
						else:
							stack.append(__[1])
							visited.append(__[1])
							ss =__[1]
							break

			# check if all the children are visited
			if s == ss :
				stack.pop()
				if len(stack) != 0:
					s = stack[len(stack) - 1]
			else:
				s = ss

			# check if se have reached the starting point
			if len(stack) == 0:
				return visited	

	# c is the count of nodes you want and if you leave it or pass -1 to the funtion the count
	# will be random from 10 to 10000
	def fill_graph_randomly(self, c = -1):
		if c == -1:
			c = (math.floor(rand.random() * 10000)) + 10
		for _ in range(c):
			# every vertex has max 100 edges
			e = math.floor(rand.random() * 102) + 1
			for __ in range(e):
				n = math.floor(rand.random() * (c)) + 1
				if n == _:
					continue
				self.add_pair(_, n, 1)

	def bfs(self, s = -2):
		d = deque()
		visited = []
		if s == -2:
			s = list(self.graph.keys())[0]
		d.append(s)
		visited.append(s)
		while d:
			s = d.popleft()
			if len(self.graph[s]) != 0:
				for __ in self.graph[s]:
					if visited.count(__[1]) < 1:
						d.append(__[1])
						visited.append(__[1])
		return visited