Added Java Solution

Author: FarheenB

Java/soln-dynamic-programming-problems/unbounded-knapsack.cpp

@@ -0,0 +1,65 @@
+/**
+ @author Farheen Bano
+  
+ Reference-
+ https://www.geeksforgeeks.org/unbounded-knapsack-repetition-items-allowed/
+*/
+
+//------------------------------------------------------------------------------
+//Memoization Approach 
+
+class Solution
+{
+    public:
+    int dp[1001][1001];
+    //Function to return max value that can be put in knapsack of capacity W.
+    int knapSack(int N, int W, int val[], int wt[]) { 
+        memset(dp,-1,sizeof(dp));
+        KS(W,wt,val,N);
+    }
+    
+    //Recursive Function
+    int KS(int W, int wt[], int val[], int N){
+        if(N==0 || W==0)
+            return 0;
+            
+        if(dp[N][W]!=-1){
+            return dp[N][W];
+        }    
+        
+        if(wt[N-1]<=W){
+            dp[N][W]=max(
+                            (val[N-1]+KS(W-wt[N-1],wt,val,N)),
+                            KS(W,wt,val,N-1)
+                        );
+            return dp[N][W];
+        }
+        dp[N][W]=KS(W,wt,val,N-1);
+        return dp[N][W];
+    }
+};
+
+//------------------------------------------------------------------------------
+//Tabulation Approach
+
+class Solution
+{
+    public:
+    int knapSack(int N, int W, int val[], int wt[]) { 
+        int dp[N+1][W+1];
+        
+        for(int i=0;i<N+1;i++){
+            for(int j=0;j<W+1;j++){
+                if(i==0||j==0){
+                    dp[i][j]=0;
+                }
+                else if(wt[i-1]<=j){
+                    dp[i][j]=max(val[i-1]+dp[i][j-wt[i-1]],dp[i-1][j]);
+                }
+                else
+                    dp[i][j]=dp[i-1][j];
+            }
+        }
+        return dp[N][W];
+    }
+};