Merge pull request #28 from amsharma44/coin_change

Coin change

coin-change.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using System.Text;
+using System.Numerics;
+using System.Diagnostics;
+
+namespace ConsoleApplication
+{
+
+    class Program
+    {
+        public static long[,] dp = new long[52, 252];
+
+        public static void Main(String[] args)
+        {
+            int[] l0 = Array.ConvertAll<string, int>(Console.ReadLine().Trim().Split(' '), e => int.Parse(e));
+            int[] coins = Array.ConvertAll<string, int>(Console.ReadLine().Trim().Split(' '), e => int.Parse(e));
+            int sum = l0[0];
+            int n = l0[1];
+            for(int i = 0; i < 52; i++)
+            {
+                for(int j = 0; j < 252; j++)
+                {
+                    dp[i, j] = -1;
+                }
+            }
+
+            Console.WriteLine(calculate(coins, sum, n - 1, 0));
+        }
+
+        public static long calculate(int[] coins, int sum, int numCoin, int i)
+        {
+            if(sum == 0)
+            {
+                return 1;
+            }
+
+            if(sum < 0)
+            {
+                return 0;
+            }
+
+            if(i > numCoin)
+            {
+                return 0;
+            }
+
+            if(dp[i, sum] == -1)
+            {
+                dp[i, sum] = calculate(coins, sum, numCoin, i + 1) + calculate(coins, sum - coins[i], numCoin, i);
+            }
+
+            return dp[i, sum];
+        }
+    }
+}