單例模式

# -*- coding: utf-8 -*-


class Singleton(object):
    _instance = {}

    def __call__(cls, *args, **kwargs):
        if cls not in Singleton._instance:
            Singleton._instance[cls] = type.__call__(cls, *args, **kwargs)
        return Singleton._instance[cls]


class Singleton2(object):
    def __new__(cls, *args, **kwargs):
        if not hasattr(cls, '_instance'):
           cls._instance = super(Singleton2, cls).__new__(cls, *args, **kwargs)
        return cls._instance


def singleton(cls, *args, **kwargs):
    instance = {}

    def wrapper():
        if cls not in instance:
            instance[cls] = cls(*args, **kwargs)
        return instance[cls]
    return wrapper

生產(chǎn)者消費(fèi)者

# -*- coding: utf-8 -*-
import time
from threading import Thread, Condition


class Producer(Thread):
    def run(self):
        global count
        while True:
            if con.acquire():
                if count > 1000:
                    con.wait()
                else:
                    count += 100
                    print self.name + " prudce 100, count = " + str(count)
                    con.notify()
                con.release()
            time.sleep(1)


class Consumer(Thread):
    def run(self):
        global count
        while True:
            if con.acquire():
                if count < 100:
                    con.wait()
                else:
                    count -= 3
                    print self.name + " Consumer 3, count = " + str(count)
                    con.notify()
                con.release()
            time.sleep(1)


if __name__ == "__main__":
    count = 500
    con = Condition()

    for i in range(2):
        p = Producer()
        p.start()

    for i in range(5):
        c = Consumer()
        c.start()

二分查找

# -*- coding: utf-8 -*-


def binarySearch(l, t):
    low, high = 0, len(l) - 1
    while low < high:
        mid = (low + high) / 2
        if l[mid] > t:
            high = mid
        elif l[mid] < t:
            low = mid + 1
        else:
            return mid
    return -1 

if __name__ == '__main__':
    l = [1, 4, 12, 45, 66, 99, 120, 444]
    print binarySearch(l, 99)

斐波那契

def fib(n):
    a, b = 0, 1
    for _ in xrange(n):
        a, b = b, a + b
    return b

fib2 = lambda n: n if n <= 2 else fib2(n - 1) + fib2(n - 2)

合并有序列表

# -*- coding: utf-8 -*-


def _recursion_merge_sort2(l1, l2, tmp):
    if len(l1) == 0 or len(l2) == 0:
        tmp.extend(l1)
        tmp.extend(l2)
        return tmp
    else:
        if l1[0] < l2[0]:
            tmp.append(l1[0])
            del l1[0]
        else:
            tmp.append(l2[0])
            del l2[0]
        return _recursion_merge_sort2(l1, l2, tmp)


def recursion_merge_sort2(l1, l2):
    return _recursion_merge_sort2(l1, l2, [])

冒泡

# -*- coding: utf-8 -*-


def bubbleSort(lists):
    count = len(lists)
    for i in range(0, count):
        for j in range(i + 1, count):
            if lists[i] > lists[j]:
                lists[i], lists[j] = lists[j], lists[i]
    return lists

插入排序

# -*- coding: utf-8 -*-


def insert_sort(lists):
    count = len(lists)
    for i in range(1, count):
        key = lists[i]
        j = i - 1
        while j >= 0:
            if lists[j] > key:
                lists[j + 1] = lists[j]
                lists[j] = key
            j -= 1
    return lists

快排

# -*- coding: utf-8 -*-


def qsort(seq):
    if seq == []:
        return []
    else:
        pivot = seq[0]
        lesser = qsort([x for x in seq[1:] if x < pivot])
        greater = qsort([x for x in seq[1:] if x >= pivot])
        return lesser + [pivot] + greater


if __name__ == "__main__":
    seq = [5, 6, 78, 9, 0, -1, 2, 3, -65, 12]
    print qsort(seq)

遍歷二叉樹

# -*- coding: utf-8 -*-


class Node(object):
    def __init__(self, data, left=None, right=None):
        self.data = data
        self.left = left
        self.right = right


tree = Node(1, Node(3, Node(7, Node(0)), Node(6)), Node(2, Node(5), Node(4)))


def lookup(root):
    """
    層次遍歷
    """
    stack = [root]
    while stack:
        current = stack.pop(0)
        print current.data
        if current.left:
            stack.append(current.left)
        if current.right:
            stack.append(current.right)


def deep(root):
    """
    深度遍歷
    """
    if not root:
        return
    print root.data
    deep(root.left)
    deep(root.right)


def maxDepth(root):
    """
    求最大樹深
    """
    if not root:
        return 0
    return max(maxDepth(root.left), maxDepth(root.right)) + 1


def isSameTree(tree_one, tree_two):
    if not tree_one and not tree_two:
        return True
    elif tree_one and tree_two:
        return tree_one.data == tree_two.data and isSameTree(tree_one.left, tree_two.right) and isSameTree(tree_one.right, tree_two.right)
    else:
        return False


if __name__ == "__main__":
    # lookup(tree)
    # deep(tree)
    maxDepth(tree)