Computer Science Study guides, Class notes & Summaries

Problem 18. Bullseye Matrix Created by Cody Team in Cody Challenge Given n (always odd), return output a that has concentric rings of the numbers 1 through (n 1)/2 around the center point. Examples: Input n = 3 Output a is [ 2 2 2 2 1 2 2 2 2 ] Input n = 5 Output a is [ 3 3 3 3 3 3 2 2 2 3 3 2 1 2 3 3 2 2 2 3 3 3 3 3 3 ]

Problem 35. Quote Doubler Created by Cody Team in Cody Challenge Given a string s1, find all occurrences of the single quote character and replace them with two occurrences of the single quote character. If there are n such occurrences in s1, then s2 will be n characters longer than s1.

Problem 62. Elapsed Time Created by Cody Team in Cody Challenge Given two date strings d1 and d2 of the form yyyy/mm/dd HH:MM:SS (assume hours HH is in 24 hour mode), determine how much time, in decimal hours, separates them. Assume d2 is always later than d1. Example: Input d1 = '2010/12/14 12:00:00' Input d2 = '2010/12/14 13:06:36' Output elapsed is 1.11

Problem 15. Find the longest sequence of 1's in a binary sequence. Created by Cody Team in Cody Challenge Given a string such as s = '011110010000000100010111' find the length of the longest string of consecutive 1's. In this example, the answer would be 4. Example: Input x = '110100111' Output y is 3

Problem 76. De-dupe Created by Cody Team in Cody Challenge Remove all the redundant elements in a vector, but keep the first occurrence of each value in its original location. So if a = [5 3 6 4 7 7 3 5 9] then dedupe(a) = [5 3 6 4 7 9]

Problem 48. Making change Created by Cody Team in Cody Challenge Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = 257.68 Output b is [2 1 0 0 1 1 0 1 0 1 1 3] Always use bigger bills/coins if possible.

Problem 74. Balanced number Created by Cody Team in Cody Challenge Given a positive integer find whether it is a balanced number. For a balanced number the sum of first half of digits is equal to the second half. Examples: Input n = 13722 Output tf is true because 1 3 = 2 2. Input n = 23567414 Output tf = true All palindrome numbers are balanced. This is partly from Project Euler, Problem 217.

Problem 147. Too mean-spirited Created by the cyclist in Community Find the mean of each consecutive pair of numbers in the input row vector. For example, x=[1 2 3] ----> y = [1.5 2.5] x=[100 0 0 0 100] ----> y = [50 0 0 50]