yanfeng42

package study.algorithm;

import edu.princeton.cs.algs4.StdOut;

public class QueueFromSevenStack<Item> {
    private boolean isRevert = false; // 是否在反转 Stack.
    private boolean isConcat = false; // 是否在拼接 Stack.

    private Stack<Item> T = new Stack<>(); // 队列尾部,用于 enqueue 入队操作.
    private Stack<Item> H = new Stack<>(); // 队列头部, 用于 dequeue 出队操作.

yanfeng42

; My answer.

#|
keypoints:
* cache tail node.
* call set-cdr!

ref:
* tips: cons build pairs, not lists. cons build pairs, not lists.   ref: https://stackoverflow.com/a/5741668
* https://medium.com/@aleksandrasays/my-other-car-is-a-cdr-3058e6743c15

yanfeng42

import codecs
import os
import shutil
import glob


def convert(file_path: str, from_encoding: str, to_encoding: str):
    utf16_path = file_path
    utf8_tmp_path = utf16_path + ".tmp"
    try:

yanfeng42

# step3.1

# check timedatectl
timedatectl

# change server timezone
sudo timedatectl set-timezone $timezone_you_need

# step3.2

yanfeng42

@task(alias='bot_p')
def bot_pomodoro():
    token = $your_robot_token
    chat_id = $robot_chat_id_with_you

    now = datetime.datetime.now()
    minute = now.minute

    tip = 'unknown error'
    if minute == 0:

yanfeng42

package life.yanfeng.study.algorithm;

import edu.princeton.cs.algs4.StdOut;

// 1.3.10 衍生 中缀转前缀
public class InfixToPrefix {
    /// 自动补全 左括号 . 反向推导表达式的原始形式.
    /// 核心思路, 也即: 双栈表达式的精髓在于: 使用同一个栈, 同时存储 操作数 和 中间运算结果.
    static String transform(String exp) {
        Stack<String> ops = new Stack<>();

yanfeng42

package life.yanfeng.study.algorithm;

import edu.princeton.cs.algs4.StdOut;

/// for 1.3.10 中缀 转 后缀. 和 1.3.9 类似的思路
public class InfixToPostfix {
    /// 自动补全 左括号 . 反向推导表达式的原始形式.
    /// 核心思路, 也即: 双栈表达式的精髓在于: 使用同一个栈, 同时存储 操作数 和 中间运算结果.
    static String transform(String exp) {
        Stack<String> ops = new Stack<>();

yanfeng42

package life.yanfeng.study.algorithm;

import edu.princeton.cs.algs4.StdOut;

// for 1.3.9
public class AutoCompleteParentheses {
    /// from 1.3.1.7 Dijkstra 的双栈表达式求值算法
    static double evaluate(String exp) {
        Stack<String> ops = new Stack<>();
        Stack<Double> vals = new Stack<>();

yanfeng42

package life.yanfeng.study.algorithm;

import edu.princeton.cs.algs4.StdOut;

// for 1.3.5
public class StackPrintCase {
    public static void printCase(Integer N, int base) {
        Stack<Integer> stack = new Stack<>();
        while (N > 0) {
            stack.push(N % base);

yanfeng42

package life.yanfeng.study.algorithm;

import edu.princeton.cs.algs4.StdOut;

// for 1.3.4
public class Parentheses<Item> {
    private Bracket<Item>[] brackets;

    Parentheses(Bracket<Item>[] brackets) {
        this.brackets = brackets;