Dynamic programming is all about storing the answers to previous sub-problems to speed up our runtimes by avoiding repeating work that has already been done. Memoization: An optimization technique used primarily to speed up computer programs by storing the results of expensive function calls and returning the cached result when the same inputs occur again. Link to Problem - https://leetcode.com/problems/coin-change-2/ You are given coins of different denominations and a total amount of money. Write a function to compute the number of combinations that make up that amount. You may assume that you have an infinite number of each kind of coin. Example 1: Input: amount = 5, coins = [1, 2, 5] Output: 4 Explanation: there are four ways to make up the amount: 5=5 5=2+2+1 5=2+1+1+1 5=1+1+1+1+1 Example 2: Input: amount = 3, coins = [2] Output: 0 Explanation: the amount of 3 cannot be made up just with coins of 2. Example 3: Input: amount = 10, coins = [10] Output: 1 ------------------------------------------------------------------------ Follow me on Instagram - https://www.instagram.com/Piyush_eon