sunbocong的博客

Given a string, return a “rotated left 2” version where the first 2 chars are moved to the end. The string length will be at least 2.left2(‘Hello’) → ‘lloHe’left2(‘java’) → ‘vaja’left2(‘Hi’) → ‘Hi’Expected Run left2(‘Hello’) → ‘lloHe’ ‘lloHe’ OK left

Given 2 strings, return their concatenation, except omit the first char of each. The strings will be at least length 1.non_start(‘Hello’, ‘There’) → ‘ellohere’non_start(‘java’, ‘code’) → ‘avaode’non_start(‘shotl’, ‘java’) → ‘hotlava’Expected Run non_s

Given 2 strings, a and b, return a string of the form short+long+short, with the shorter string on the outside and the longer string on the inside. The strings will not be the same length, but they may be empty (length 0).combo_string(‘Hello’, ‘hi’) → ‘hiH

Given a string, return a version without the first and last char, so “Hello” yields “ell”. The string length will be at least 2.without_end(‘Hello’) → ‘ell’without_end(‘java’) → ‘av’without_end(‘coding’) → ‘odin’Expected Run without_end(‘Hello’) → ‘el

Given a string of even length, return the first half. So the string “WooHoo” yields “Woo”.first_half(‘WooHoo’) → ‘Woo’first_half(‘HelloThere’) → ‘Hello’first_half(‘abcdef’) → ‘abc’Expected Run first_half(‘WooHoo’) → ‘Woo’ ‘Woo’ OK first_half(‘HelloTh

Given a string, return the string made of its first two chars, so the String “Hello” yields “He”. If the string is shorter than length 2, return whatever there is, so “X” yields “X”, and the empty string “” yields the empty string “”.first_two(‘Hello’) → ‘

Given a string, return a new string made of 3 copies of the last 2 chars of the original string. The string length will be at least 2.extra_end(‘Hello’) → ‘lololo’extra_end(‘ab’) → ‘ababab’extra_end(‘Hi’) → ‘HiHiHi’Expected Run extra_end(‘Hello’) → ‘l

Given an “out” string length 4, such as “”, and a word, return a new string where the word is in the middle of the out string, e.g. “”.make_out_word(‘’, ‘Yay’) → ‘’make_out_word(‘’, ‘WooHoo’) → ‘’make_out_word(‘[[]]’, ‘word’) → ‘[[word]

The web is built with HTML strings like “Yay” which draws Yay as italic text. In this example, the “i” tag makes and which surround the word “Yay”. Given tag and word strings, create the HTML string with tags around the word, e.g. “Yay”.make_tags(‘i’, ‘Y

Given two strings, a and b, return the result of putting them together in the order abba, e.g. “Hi” and “Bye” returns “HiByeByeHi”.make_abba(‘Hi’, ‘Bye’) → ‘HiByeByeHi’make_abba(‘Yo’, ‘Alice’) → ‘YoAliceAliceYo’make_abba(‘What’, ‘Up’) → ‘WhatUpUpWhat’Ex

Given a string name, e.g. “Bob”, return a greeting of the form “Hello Bob!”.hello_name(‘Bob’) → ‘Hello Bob!’hello_name(‘Alice’) → ‘Hello Alice!’hello_name(‘X’) → ‘Hello X!’Expected Run hello_name(‘Bob’) → ‘Hello Bob!’ ‘Hello Bob!’ OK hello_name(‘Alic

Given 2 strings, a and b, return the number of the positions where they contain the same length 2 substring. So “xxcaazz” and “xxbaaz” yields 3, since the “xx”, “aa”, and “az” substrings appear in the same place in both strings.string_match(‘xxcaazz’, ‘xxb

Given an array of ints, return True if the sequence of numbers 1, 2, 3 appears in the array somewhere.array123([1, 1, 2, 3, 1]) → Truearray123([1, 1, 2, 4, 1]) → Falsearray123([1, 1, 2, 1, 2, 3]) → TrueExpected Run array123([1, 1, 2, 3, 1]) → True Tru

Given an array of ints, return True if one of the first 4 elements in the array is a 9. The array length may be less than 4.array_front9([1, 2, 9, 3, 4]) → Truearray_front9([1, 2, 3, 4, 9]) → Falsearray_front9([1, 2, 3, 4, 5]) → FalseExpected Run arra

Given an array of ints, return the number of 9’s in the array.array_count9([1, 2, 9]) → 1array_count9([1, 9, 9]) → 2array_count9([1, 9, 9, 3, 9]) → 3Expected Run array_count9([1, 2, 9]) → 1 1 OK array_count9([1, 9, 9]) → 2 2 OK array_count9([1, 9, 9

Given a string, return the count of the number of times that a substring length 2 appears in the string and also as the last 2 chars of the string, so “hixxxhi” yields 1 (we won’t count the end substring).last2(‘hixxhi’) → 1last2(‘xaxxaxaxx’) → 1last2(‘a

Given a non-empty string like “Code” return a string like “CCoCodCode”.string_splosion(‘Code’) → ‘CCoCodCode’string_splosion(‘abc’) → ‘aababc’string_splosion(‘ab’) → ‘aab’Expected Run string_splosion(‘Code’) → ‘CCoCodCode’ ‘CCoCodCode’ OK string_splo

Given a string, return a new string made of every other char starting with the first, so “Hello” yields “Hlo”.string_bits(‘Hello’) → ‘Hlo’string_bits(‘Hi’) → ‘H’string_bits(‘Heeololeo’) → ‘Hello’Expected Run string_bits(‘Hello’) → ‘Hlo’ ‘Hlo’ OK stri

Given a string and a non-negative int n, we’ll say that the front of the string is the first 3 chars, or whatever is there if the string is less than length 3. Return n copies of the front;front_times(‘Chocolate’, 2) → ‘ChoCho’front_times(‘Chocolate’, 3)

Given a string and a non-negative int n, return a larger string that is n copies of the original string.string_times(‘Hi’, 2) → ‘HiHi’string_times(‘Hi’, 3) → ‘HiHiHi’string_times(‘Hi’, 1) → ‘Hi’Expected Run string_times(‘Hi’, 2) → ‘HiHi’ ‘HiHi’ OK st

Given a string, we’ll say that the front is the first 3 chars of the string. If the string length is less than 3, the front is whatever is there. Return a new string which is 3 copies of the front.front3(‘Java’) → ‘JavJavJav’front3(‘Chocolate’) → ‘ChoChoC

Given a string, return a new string where the first and last chars have been exchanged.front_back(‘code’) → ‘eodc’front_back(‘a’) → ‘a’front_back(‘ab’) → ‘ba’Expected Run front_back(‘code’) → ‘eodc’ ‘eodc’ OK front_back(‘a’) → ‘a’ ‘a’ OK front_back(

Given a non-empty string and an int n, return a new string where the char at index n has been removed. The value of n will be a valid index of a char in the original string (i.e. n will be in the range 0…len(str)-1 inclusive).missing_char(‘kitten’, 1) → ‘k

Given a string, return a new string where "not " has been added to the front. However, if the string already begins with “not”, return the string unchanged.not_string(‘candy’) → ‘not candy’not_string(‘x’) → ‘not x’not_string(‘not bad’) → ‘not bad’Expect

Given 2 int values, return True if one is negative and one is positive. Except if the parameter “negative” is True, then return True only if both are negative.pos_neg(1, -1, False) → Truepos_neg(-1, 1, False) → Truepos_neg(-4, -5, True) → TrueExpected R

Given an int n, return True if it is within 10 of 100 or 200. Note: abs(num) computes the absolute value of a number.near_hundred(93) → Truenear_hundred(90) → Truenear_hundred(89) → FalseExpected Run near_hundred(93) → True True OK near_hundred(90) →

Given 2 ints, a and b, return True if one if them is 10 or if their sum is 10.makes10(9, 10) → Truemakes10(9, 9) → Falsemakes10(1, 9) → TrueExpected Run makes10(9, 10) → True True OK makes10(9, 9) → False False OK makes10(1, 9) → True True OK makes

We have a loud talking parrot. The “hour” parameter is the current hour time in the range 0…23. We are in trouble if the parrot is talking and the hour is before 7 or after 20. Return True if we are in trouble.parrot_trouble(True, 6) → Trueparrot_trouble(

Given an int n, return the absolute difference between n and 21, except return double the absolute difference if n is over 21.diff21(19) → 2diff21(10) → 11diff21(21) → 0Expected Run diff21(19) → 2 2 OK diff21(10) → 11 11 OK diff21(21) → 0 0 OK diff

Given two int values, return their sum. Unless the two values are the same, then return double their sum.sum_double(1, 2) → 3sum_double(3, 2) → 5sum_double(2, 2) → 8Expected Run sum_double(1, 2) → 3 3 OK sum_double(3, 2) → 5 5 OK sum_double(2, 2) →

We have two monkeys, a and b, and the parameters a_smile and b_smile indicate if each is smiling. We are in trouble if they are both smiling or if neither of them is smiling. Return True if we are in trouble.monkey_trouble(True, True) → Truemonkey_trouble

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