add Positives solution

Author: jakovmitrovski

medium300/Positives.java

@@ -0,0 +1,49 @@
+package medium300;
+
+import java.util.*;
+
+public class Positives {
+
+    int [][]dp = new int[51][20001];
+    Set<Integer> s = new HashSet<>();
+    int res(int []a, int ind, int n, int sum){
+        //System.out.println(ind + " " + sum + " " + dp[ind][sum+10000]);
+        if (dp[ind][sum+10000] != -1) return dp[ind][sum+10000];
+        //System.out.println(ind + " " + sum);
+        if (ind == n && sum >= 0) {
+            dp[ind][sum + 10000] = 0;
+            s.add(sum);
+            return 1;
+        }
+        else if (ind==n) {
+            dp[ind][sum + 10000] = 0;
+            return 0;
+        }
+        int left = res(a, ind+1, n, sum+a[ind]), right = res(a, ind+1, n, sum-a[ind]);
+        return dp[ind][sum+10000] = left+right;
+
+    }
+
+    public int getPositiveCount(int[] numbers) {
+
+        s.clear();
+        for (int i=0; i<=numbers.length; i++)
+            for (int j=0; j<20001; j++) dp[i][j] = -1;
+        res(numbers, 0, numbers.length, 0);
+        return s.size();
+    }
+
+//    public static void main(String[] args) {
+//        Positives p = new Positives();
+//        System.out.println(p.getPositiveCount(new int[]{13, 2, 17, 11, 18}));
+//        //System.out.println(p.getPositiveCount(new int[]{3, 2, 1}));
+//        System.out.println(p.getPositiveCount(
+//                new int[]{40, 66, 63, 73, 52, 4, 47, 36, 100, 83, 62, 76, 13,
+//                        31, 28, 1, 93, 74}));
+//        System.out.println(p.getPositiveCount(
+//
+//                new int[]{70, 77, 78, 85, 77, 66, 82, 80, 74, 62, 92, 20, 52,
+//                        82, 9, 61, 47, 84, 43, 59,43,1,3,5,3,5,3,4,3,4,3,4,5,45,3,2,2,4,5,5,3,2,2,3,4,3,3,4,5}));
+//    }
+}
+