DFS, TopologicalSort

g = {
    0: [[1, 1]],
    1: [[2, 1], [3, 1], [5, 1], [6, 1]],
    2: [[6, 1]],
    3: [[7, 1]],
    4: [[6, 1]],
    5: [],
    6: [[7, 1]],
    7: []
}

from collections import deque
 
def dfs(graph, start):
    color = dict().fromkeys(graph.keys(), 'White')
    color[start] = 'Grey'
    path = {start: start}
    order = list()
    stack = deque()
    stack.append(start)
    while stack:
        current = stack.pop()
        for edge, dist in graph[current]:
            if color[edge] == 'White':
                color[edge] = 'Grey'
                path[edge] = current
                stack.append(edge)
            color[current] = 'Black'
    return path.keys()

from collections import deque
 
 
def dfs(graph, start):
    color = dict().fromkeys(graph.keys(), 'White')
    color[start] = 'Grey'
    path = {start: start}
    stack = deque()
    stack.append(start)
    while stack:
        current = stack.pop()
        for edge, dist in graph[current]:
            if color[edge] == 'White':
                color[edge] = 'Grey'
                path[edge] = current
                stack.append(edge)
            color[current] = 'Black'
    return path.keys()
 
 
def topological_sort(graph):
    visited = list()
    for i in graph.keys():
        visited = visited + [j for j in dfs(graph, i) if j not in visited][::-1]
    return visited[::-1]
 
g1 = {
    0: [[4, 1]],
    1: [[5, 1], [2, 1]],
    2: [],
    3: [[5, 1]],
    4: [[7, 1]],
    5: [[7, 1]],
    6: [[7, 1]],
    7: []
}
 
g2 = {
    0: [[4, 1]],
    1: [[6, 1], [5, 1], [3, 1]],
    2: [[5, 1]],
    3: [[7, 1]],
    4: [[7, 1]],
    5: [],
    6: [[7, 1]],
    7: []
}
 
print(topological_sort(g1))  # [6, 3, 1, 5, 2, 0, 4, 7]
print(topological_sort(g2))  # [2, 1, 6, 5, 3, 0, 4, 7]