归档 2016

利用Python计算1000以内自然数的约数个数，然后通过matplotlib绘制统计图。

绘制图片为约数个数的散点图及其分布情况的条形图。

Python代码：

import collections
import matplotlib.pyplot as plt

def countDivisors(num):
    ans = 1
    x = 2
    while x * x <= num:
        cnt = 1
        while num % x == 0:
            cnt += 1
            num /= x
        ans *= cnt
        x += 1
    return ans * (1 ...

方法I 从1到n枚举，判断是否可以整除

时间复杂度 O(n)

Python代码：

def countDivisors(num):
    return sum(num % i == 0 for i in range(1, num + 1))

方法II 从1到sqrt(n)枚举，判断是否可以整除

时间复杂度 O( sqrt(n) )

Python代码：

def countDivisors(num):
    cnt = 0
    sqrt = int(num ...

在下方文本框内输入有向图JSON（[source, target, value]）：

[[0,1,10], [1,0,1], [1,2,5], [2,0,5]]

生成力导向图

上例的源码如下 ...

题目描述：

LeetCode 460. LFU Cache

Design and implement a data structure for Least Frequently Used (LFU) cache. It should support the following operations: get and set.

get(key) - Get the value (will always be positive) of the key if the ...

题目描述：

LeetCode 465. Optimal Account Balancing

A group of friends went on holiday and sometimes lent each other money. For example, Alice paid for Bill's lunch for $10. Then later Chris gave Alice $5 for a taxi ride. We can ...