Hodgepodge

Introduction

Technically indexes and pointers are not the same thing, but in certain circumstances they can be considered the same for naming purposes (imprecise/sloppy). In the diagram below there are two list indexes (A and B). In this circumstance you might use the name index and pointer interchangeable.

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Project #1

Given the diagram above (list and pointers/indexes), find all of the integer pairs that sum to 6.

Use the following algorithm (The list must be sorted in ascending order)

idxa = 0 idxb = len(nums) - 1 target = 6 while idxa < idxb: total = nums[idxa] + nums[idxb] if total == target: print-the-match-info if total >= target: move-an-index else: move-an-index

Turn the algorithm into a function. Turn it into a generator?

Write a program that calls the function with the information above. Print each pair and the total number of pairs.

Question: Why must the list be sorted for this algorithm?

Project #2

Create a program that allows a user to enter a list and a target sum.

Questions:

The list must be sorted. Do you sort it in the function or the main program?

What happens if the list is not sorted?

What happens if the list is in descending order?

Project #3

Given a string, use two pointers/indexes to find the longest sequence of the same character. Display the character and its location in the list.

For example:

string = 'aghrsssssdsfgggghaannozzxzttrrrrvvvvvvzzzz' ... ... ... print the longest sequence character is "V" print the location is index 32 to 37 (inclusive)

Create a program that allows a user to enter a string. Find the longest substring matching a single character. Display the character and its location.

Project #4

See Project #3.

Do the same thing but find the longest sequence of non-matching characters.

Create a program that allows a user to enter a string. Find the longest substring of non-matching characters. Display the characters and their location in the list.