EdisonChendi

import unittest
import string
import collections
from pprint import pprint

# def print(*args, **kwargs):
#     pass

def make_table(letters, width):
    table = {}

EdisonChendi

import unittest
import re

def permutations(ops, len):
    if len == 1:
        return [[op] for op in ops]
    l = []
    for i, op in enumerate(ops):
        for s in permutations(ops, len-1):
            l.append([op,]+s)

EdisonChendi

#coding:UTF-8

from collections import defaultdict

def find_anagrams(setence):
    words = set(setence.split())
    dd = defaultdict(list)
    for w in words: # O(nklgk)
        dd["".join(sorted(w))].append(w)
    return {k:v for k, v in dd.items() if len(v) > 1} # O(n)

EdisonChendi

#coding:UTF-8

class Graph:

    def __init__(self):
        # use dict to store the graph
        # the number of keys in self.ves is the number of vertices in the graph
        # the total number of values(list) is the sum of degree of each vertex
        self.ves = {}

EdisonChendi

#coding:UTF-8

from random import randint
from functools import partial
from counting_sort import counting_sort

'''
for simplicity: use base 10
b - base
k - range of values of keys of the input

EdisonChendi

#coding:UTF-8

from random import randint
from math import inf

'''
running time: O(n+k)
'''

def counting_sort(arr, n, k, key=lambda x: x):

EdisonChendi

#coding:UTF-8

'''
notes on R5

What is a data structure?
Algorithms for you to query update store information

BST
query:

EdisonChendi

#coding:UTF-8

def heapify(arr, i):
    # O(lgn)
    left_idx = 2*i+1
    if left_idx >= len(arr):
        return
    right_idx = left_idx + 1
    if right_idx >= len(arr):
        left = arr[left_idx]

EdisonChendi

#coding:UTF-8

import math

def merge_sort(l):

    if len(l) <= 1:
        return l

    mid_idx = (len(l)-0)//2

EdisonChendi

#codint:UTF-8

def insertion_sort(l):
    if len(l) <= 1:
        return l
    for i in range(1, len(l)):
        key = l[i]
        for j in reversed(range(0, i)):
            c = l[j]
            if c > key: