senvey

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

senvey

Site List

• http://www.salttiger.com/
• http://www.avaxsearch.com/
• http://it-ebooks.info/

Image Site

• https://3cvpkfx4gdnkcduj.onion.cab/search.php
• http://bt8.nl/ebook.php

senvey

#!/bin/env python

import math
import tensorflow as tf

from tensorflow.examples.tutorials.mnist import input_data as mnist_data
print("Tensorflow version " + tf.__version__)

# https://stackoverflow.com/questions/47068709/your-cpu-supports-instructions-that-this-tensorflow-binary-was-not-compiled-to-u
import os

senvey

CREATE INDEX
    example_by_business_id
ON TABLE
    example_table (businessID)
AS 'COMPACT' WITH DEFERRED REBUILD;

ALTER INDEX example_by_business_id ON example_table REBUILD;

senvey

# Change the magic key to `^A`:
set-option -g prefix C-a
unbind-key C-b
bind-key a send-prefix

### Some familiar `screen`-like movement bindings ###
# `^A^A` to toggle between the last two windows
bind-key C-a last-window
# `^A space` to move to the next window
bind-key Space next-window

senvey

killall ssh-agent; eval `ssh-agent`

senvey

"""
Given integers L and t, a string Pattern forms an (L, t)-clump inside a (larger) string Genome if there is an interval of Genome of length L in which Pattern appears at least t times. For example, TGCA forms a (25,3)-clump in the following Genome: gatcagcataagggtcccTGCAaTGCAtgacaagccTGCAgttgttttac.

Clump Finding Problem

Find patterns forming clumps in a string.

Given: A string Genome, and integers k, L, and t.

Return: All distinct k-mers forming (L, t)-clumps in Genome.

senvey

def count(array, n):
    
    # starting point
    left, right = 0, len(array)
    while left < right:
        mid = (left + right) / 2
        if array[mid] >= n:
            right = mid
        else:
            left = mid + 1

senvey

# http://leetcode.com/2011/05/a-distance-maximizing-problem.html

def max_distance(array):
    
    # collect possible starting points
    # alternative: only record index without the num
    starts = [(array[0], 0)]
    for i, each in enumerate(array):
        if each < starts[-1][0]:
            starts.append((each, i))

senvey

def successor(node):
    if node.right:
        c = node.right
        while c.left:
            c = c.left
        return c
    
    n, p = node, node.parent
    # note: check if p is not None
    while p and n != p.left: