zhang-zedong

puts "Hello, gist!"

zhang-zedong

class Order < ApplicationRecord
  belongs_to :user
  has_many :order_items

  def pay!
    self.update_columns(is_paid: true)
  end
  include AASM
  aasm do
    state :order_placed, :initial => true

zhang-zedong

#include <stdio.h>

int main(int argc, const char * argv[]) {
    int i = 0;
    int j = 0;
    while (j != 100) {
        i = (i+1)%13;
        j++;
        if (j % 4==0) {
            printf("%d ", i);

zhang-zedong

//
//  main.c
//  work-demo
//
//  Created by 黄超 on 2017/4/26.
//  Copyright © 2017年 黄超. All rights reserved.
//

#include <stdio.h>
#include <stdlib.h>

zhang-zedong

Ruby on Rails Cheatsheet

Architecture

Create a new application

Install the Rails gem if you haven't done so before

zhang-zedong

#include<stdio.h>
void main(){
    int i,j,n;
    for(n=0;n<6;n++){
        for(i=n,j=0;j<9;i++,j++){
            printf("%c",'A'+i);
            if(i==8){
                i=-1;
            }
        }

zhang-zedong

# Add `~/bin` to the `$PATH`
export PATH="$HOME/bin:$PATH";

# Load the shell dotfiles, and then some:
# * ~/.path can be used to extend `$PATH`.
# * ~/.extra can be used for other settings you don’t want to commit.
for file in ~/.{path,bash_prompt,exports,aliases,functions,extra}; do
    [ -r "$file" ] && [ -f "$file" ] && source "$file";
done;
unset file;

zhang-zedong

#!/usr/bin/env bash
# aws s3 cp --acl public-read post-install.sh s3://zedong-hpc-bucket/post-install.sh
# This script runs as root.

# Disable Intel Hyper-Threading Technology at runtime
for cpunum in $(cat /sys/devices/system/cpu/cpu*/topology/thread_siblings_list | cut -s -d, -f2- | tr ',' '\n' | sort -un)
do
	echo 0 > /sys/devices/system/cpu/cpu$cpunum/online
done

zhang-zedong

# check if a tree can divid into 3 equal subtree, just alowing cut at root .
class Node:
    def __init__(self, val=None) -> None:
        self.val = val
        self.children = []

def generate_tree(inputs):
    dic = {}
    dic[1] = Node(1)
    for pair in inputs:

zhang-zedong

# check if a tree can divid into 3 equal subtree, just alowing cut at root .
class Node:
    def __init__(self, val=None) -> None:
        self.val = val
        self.children = []

def generate_tree(inputs):
    dic = {}
    dic[1] = Node(1)
    for pair in inputs: