1 unique() 统计list中的不同值时,返回的是array.它有三个参数,可分别统计不同的量,返回的都是array. 当list中的元素也是list时,尽量不要用这种方法. import numpy as np a = [1,5,4,2,3,3,5] # 返回一个array print(np.unique(a)) # 返回该元素在list中第一次出现的索引 print(np.unique(a,return_index=True)) # 返回原list中每个元素在新的list中对应的索引…

一.序列Series,很像numpy中的array数组,可以由列表.元组.字典.numpy中的array来初始化 >>> from pandas import Series >>> s = Series([0.1, 1.2, 2.3, 3.4, 4.5]) >>> s 0.1 1.2 2.3 3.4 4.5 dtype: float64 2.序列也可以由标签组成,默认是由数字表示. >>> s = Series([0.1, 1.2,…

Title: https://leetcode.com/problems/unique-paths/ A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to reach the bo…

参考:https://www.cnblogs.com/xxswkl/p/11009059.html 1 unique() 统计list中的不同值时,返回的是array.它有三个参数,可分别统计不同的量,返回的都是array. 当list中的元素也是list时,尽量不要用这种方法. import numpy as np a = [1,5,4,2,3,3,5] # 返回一个array print(np.unique(a)) # [1 2 3 4 5] # 返回该元素在list中第一次出现的索引 pr…

Consider the string s to be the infinite wraparound string of "abcdefghijklmnopqrstuvwxyz", so s will look like this: "...zabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd....". Now we have another string p. Your job is to find…

A string such as "word" contains the following abbreviations: ["word", "1ord", "w1rd", "wo1d", "wor1", "2rd", "w2d", "wo2", "1o1d", "1or1", "…

Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10n. Example: Given n = 2, return 91. (The answer should be the total numbers in the range of 0 ≤ x < 100, excluding [11,22,33,44,55,66,77,88,99]) Hint: A direct…

An abbreviation of a word follows the form <first letter><number><last letter>. Below are some examples of word abbreviations: a) it --> it (no abbreviation) 1 b) d|o|g --> d1g 1 1 1 1---5----0----5--8 c) i|nternationalizatio|n --&…

Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 这道题实际上是Catalan Number卡塔兰数的一个例子,如果对卡塔兰数不熟悉的童鞋可能真…

Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 confused what "{1,#,2…