Refactoring.

LeetCode/src/LeetCode.Challenges/CoinChangeII/BacktrackingSolution.cs → LeetCode/src/LeetCode.Challenges/Problems05xx/N_0518_CoinChangeII/BacktrackingSolution.cs

@@ -1,4 +1,4 @@
-namespace LeetCode.Challenges.CoinChangeII;
+namespace LeetCode.Challenges.Problems05xx.N_0518_CoinChangeII;
 
 public static class BacktrackingSolution
 {

LeetCode/src/LeetCode.Challenges/Problems05xx/N_0518_CoinChangeII/Description.md

@@ -0,0 +1,43 @@
+# Coin Change II (#518)
+
+You are given an integer array coins representing coins of different denominations 
+and an integer amount representing a total amount of money.
+
+Return the number of combinations that make up that amount.  
+If that amount of money cannot be made up by any combination of the coins, return 0.
+
+You may assume that you have an infinite number of each kind of coin.
+
+The answer is guaranteed to fit into a signed 32-bit integer.
+
+## Examples
+
+### Example 0:
+
+Input: `coins = [1, 2]`, `amount = 5`  
+Output: `3`  
+Explanation:  
+`5 = 1 + 1 + 1 + 1 + 1`  
+`5 = 1 + 1 + 1 + 2`  
+`5 = 1 + 2 + 2`  
+
+### Example 1:
+
+Input: `coins = [1, 2, 5]`, `amount = 5`  
+Output: `4`  
+Explanation:  
+`5 = 1 + 1 + 1 + 1 + 1`  
+`5 = 1 + 1 + 1 + 2`  
+`5 = 1 + 2 + 2`  
+`5 = 5`  
+
+### 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`

LeetCode/src/LeetCode.Challenges/CoinChangeII/RecursionWithMemo.cs → LeetCode/src/LeetCode.Challenges/Problems05xx/N_0518_CoinChangeII/RecursionWithMemo.cs

@@ -1,4 +1,4 @@
-namespace LeetCode.Challenges.CoinChangeII;
+namespace LeetCode.Challenges.Problems05xx.N_0518_CoinChangeII;
 
 public static class RecursionWithMemo
 {

LeetCode/tests/LeetCode.Challenges.UnitTests/CoinChangeII/BacktrackingSolutionTests.cs → LeetCode/tests/LeetCode.Challenges.UnitTests/Problems05xx/N_0518_CoinChangeII/BacktrackingSolutionTests.cs

@@ -1,8 +1,8 @@
-using LeetCode.Challenges.CoinChangeII;
-using Xunit;
+using LeetCode.Challenges.Problems05xx.N_0518_CoinChangeII;
 using Shouldly;
+using Xunit;
 
-namespace LeetCode.Challenges.UnitTests.CoinChangeII;
+namespace LeetCode.Challenges.UnitTests.Problems05xx.N_0518_CoinChangeII;
 
 public class BacktrackingSolutionTests
 {

LeetCode/tests/LeetCode.Challenges.UnitTests/CoinChangeII/RecursionWithMemoTests.cs → LeetCode/tests/LeetCode.Challenges.UnitTests/Problems05xx/N_0518_CoinChangeII/RecursionWithMemoTests.cs

@@ -1,8 +1,8 @@
-using LeetCode.Challenges.CoinChangeII;
+using LeetCode.Challenges.Problems05xx.N_0518_CoinChangeII;
 using Shouldly;
 using Xunit;
 
-namespace LeetCode.Challenges.UnitTests.CoinChangeII;
+namespace LeetCode.Challenges.UnitTests.Problems05xx.N_0518_CoinChangeII;
 
 public class RecursionWithMemoTests
 {

LeetCode/tests/LeetCode.Challenges.UnitTests/CoinChangeII/TestData.cs → LeetCode/tests/LeetCode.Challenges.UnitTests/Problems05xx/N_0518_CoinChangeII/TestData.cs

@@ -1,6 +1,6 @@
 using System.Collections;
 
-namespace LeetCode.Challenges.UnitTests.CoinChangeII;
+namespace LeetCode.Challenges.UnitTests.Problems05xx.N_0518_CoinChangeII;
 
 public class TestData : IEnumerable<object[]>
 {