Create CountSubsetsWithSumK.java

Author: harshithasudhakar

Dynamic Programming/2D/CountSubsetsWithSumK.java

@@ -0,0 +1,36 @@
+import java.util.*;
+import java.io.*;
+
+public class CountSubsetsWithSumK { //Assuming the elements of the array are positive integers
+    public static int findWays(int num[], int tar) {
+        int n = num.length;
+        int mod = 1000000007;
+
+        int[][] dp = new int[n][tar+1];
+
+        for(int i = 0; i<n; i++){
+            dp[i][0] = 1;
+        }
+
+        if(num[0]<= tar){
+            dp[0][num[0]] = 1;
+        }
+
+        if(num[0] == 0){
+            dp[0][0] = 2;
+        }
+
+        for(int i = 1; i<n; i++){
+            for(int j = 0; j<tar+1; j++){
+                int notPick = dp[i-1][j];
+                int pick = 0;
+                if(j>=num[i]){
+                    pick = dp[i-1][j-num[i]];
+                }
+                dp[i][j] = (pick + notPick) % mod;
+            }
+        }
+
+        return dp[n-1][tar];
+    }
+}