原创 leetcode 125. Valid Palindrome | 迴文string
Description Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring
2020-02-26 04:51:53
原创 leetcode 121. Best Time to Buy and Sell Stock | 最大差值和最大子序列關係
Descrpition Say you have an array for which the ith element is the price of a given stock on day i. If you were onl
2020-02-26 04:51:52
原创 【LDA|ML】西瓜書習題3.4
from XiguaData import * import numpy as np x, d = load_data_3d0a() # 已知西瓜數據3.0a前8個分類爲0，其餘分類爲1 x0 = x[:8] d0 = d[:8] x
2020-02-26 04:51:52
原创 【python|ML】k-fold/leave-one-out 方法在對率迴歸實現（西瓜書習題3.4，數據UCI-iris）
# 經驗：梯度下降要讓目標確實減小（或者增大），此程序tempsum需要減小，故要着重檢查！！ import numpy as np def dlhg(x, d): x = np.c_[x, np.ones(d.shape[
2020-02-26 04:51:52
原创 [京東面試問題] 求n=100w個數裏面的前k=100個
# 基本思路 最複雜的方法莫過於全部排序, 複雜度nlgn. 結合求100w個數裏面最大的一個數(即求max), 不需全排序, 只需開一個變量, 遍歷一次記錄最大值即可.那麼很自然的想到, 求前k個就是開一個k大小的數組, 把歷史最大
2018-08-24 05:29:46
原创 leetcode 205. Isomorphic Strings | str中字母計數(dict)與定位
Description Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters i
2018-08-24 05:29:46
原创 leetcode 242. Valid Anagram | Map
# Description Given two strings s and t, write a function to determine if t is an anagram of s. For example,s = "an
2018-08-24 05:29:45
1
原创 leetcode 202. Happy Number | 循環檢測
Description Write an algorithm to determine if a number is “happy”. A happy number is a number defined by the following
2018-08-24 05:29:45
4
原创 leetcode 204. Count Primes
Description Count the number of prime numbers less than a non-negative number, n. My solution 原始方案 比較樸素的想法就是迭代的找下去, 然
2018-08-24 05:29:45
原创 leetcode 167. Two Sum II - Input array is sorted
Descrpition Given an array of integers that is already sorted in ascending order, find two numbers such that they add u
2018-08-24 05:29:45
1
原创 leetcode 234. Palindrome Linked List
Reversing a list is not considered “O(1) space” It is a common misunderstanding that the space complexity of a prog
2018-08-24 05:29:45
原创 leetcode 203. Remove Linked List Elements | 遞歸的更多理解
Description Remove all elements from a linked list of integers that have value val. Example Given: 1 –> 2 –> 6 –> 3 –>
2018-08-24 05:29:45
原创 leetcode 225. Implement Stack using Queues
Description Implement the following operations of a stack using queues. push(x) – Push element x onto stack. pop() – R
2018-08-24 05:29:45
原创 leetcode 168. Excel Sheet Column Title | 進制轉化
Description Given a positive integer, return its corresponding column title as appear in an Excel sheet. For example: 1
2018-08-24 05:29:44
2