Merge pull request #506 from RAUNAK-PANDEY/Raunak

Unbounded Knapsack in C++ #441

Author: smv1999

Dynamic Programming/Unbounded_Knapsack.cpp

@@ -0,0 +1,81 @@
+//Link: https://practice.geeksforgeeks.org/problems/knapsack-with-duplicate-items4201/1
+
+/*
+Knapsack with Duplicate Items : 
+Given a set of N items, each with a weight and a value, and a weight limit W. Find the maximum value of a collection containing any of the N items any number of times so that the total weight is less than or equal to W.
+
+ 
+
+Example 1:
+
+Input: N = 2, W = 3
+val[] = {1, 1}
+wt[] = {2, 1}
+Output: 3
+Explaination: Pick the 2nd element thrice.
+ 
+
+Example 2:
+
+Input: N = 4, W = 8
+val[] = {1, 4, 5, 7}
+wt[] = {1, 3, 4, 5}
+Output: 11
+Explaination: The optimal choice is to 
+pick the 2nd and 4th element.*/
+// Initial Template for C++
+
+#include <bits/stdc++.h>
+using namespace std;
+
+ // } Driver Code Ends
+// User function Template for C++
+
+class Solution{
+public:
+    int knapSack(int N, int W, int val[], int wt[])
+    {
+        // code here
+        int dp[N+1][W+1];
+        memset(dp,-1,sizeof(dp));
+        
+        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;
+                }
+                //Here if weight is less than j it wont be considered processed and we will consider it multiple times. that's why we write val[i-1]+dp[i][j-wt[i-1]] instead of val[i-1]+dp[i-1][j-wt[i-1]]
+                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];
+    }
+};
+
+// { Driver Code Starts.
+
+int main(){
+    int t;
+    cin>>t;
+    while(t--){
+        int N, W;
+        cin>>N>>W;
+        int val[N], wt[N];
+        for(int i = 0;i < N;i++)
+            cin>>val[i];
+        for(int i = 0;i < N;i++)
+            cin>>wt[i];
+        
+        Solution ob;
+        cout<<ob.knapSack(N, W, val, wt)<<endl;
+    }
+    return 0;
+}  // } Driver Code Ends