You're an industrious programmer that lives off the grid. The local well that you use to fetch water has gone dry, so you've decided to collect rain water to filter; however, your collection device isn't flat.
Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water your collection device is able to trap after raining.
OOP Design is a good exercise on how to split up our system into different objects/classes. The main difficulty with problems like these are that they are open-ended and force you to think abstractly and creatively. One of the other main goals of this exercise is to be able to draw out diagrams to help with communicating abstract ideas before they are implemented in code. These problems are language agnostic.
PROMPT: Using object oriented programming principles, class diagrams and activity diagrams, design an ATM.
We are being explicit here, however, you might not get this luxury from an interviewer as they might just ask, "Using object oriented design, design an ATM".
Given a target sum and an array of positive integers, return true if any combination of numbers in the array can add to the target. Each number in the array may only be used once. Return false if the numbers cannot be used to add to the target sum.
subsetSum(2, [1, 10, 5, 3]); // false
subsetSum(10, [1, 10, 5, 3]); // true
subsetSum(9, [1, 10, 5, 3]); // true
You are given the dimensions of a grid, m and n. Starting from the top left, or (0,0), you want to end up making your way to the bottom right corner. The only two moves you can make are to go one space directly to your right, or one space directly down. Write a function that can help you determine how many unique paths you can take between these two corners.