added 2 more questions (codedecks-in#18)

* added 2 more questions

* Update README.md

Co-authored-by: Gourav Rusiya <[email protected]>

Author: Rudra407

Diff for: C++/Degree-of-an-Array.cpp

@@ -0,0 +1,38 @@
+/*
+*
+*
+* Runtime : 38 ms
+* Memory  : 53.3 MB
+*
+*
+*/
+
+class Solution {
+    public int findShortestSubArray(int[] nums) {
+        Map<Integer, Integer> left = new HashMap(), right = new HashMap(), count = new HashMap();
+ 
+        //find the leftmost and rightmost index of each characters
+        for(int i= 0;i<nums.length; i++)
+        {
+            int x =nums[i];
+            if(left.get(x) == null) 
+                left.put(x, i);
+            
+            right.put(x, i);
+            count.put(x, count.getOrDefault(x, 0) + 1);
+        }
+        
+        int ans = nums.length;
+        int degree  = Collections.max(count.values());
+        
+        //find min distance between subarrays with same degree
+        for(int x: count.keySet())
+        {
+            if(count.get(x) == degree)
+            {
+                ans = Math.min(ans , right.get(x) - left.get(x) + 1);
+            }
+        }
+        return ans;   
+    }
+}

Diff for: C++/Partition-Equal-Subset-Sum.cpp

@@ -0,0 +1,62 @@
+/*
+*
+*
+* Runtime : 80ms
+* Memory : 9.6 MB
+* Logic : 0/1 knapsack concept used to calculate subsetSum
+*/
+class Solution {
+public:
+    
+    // using 0/1 knapsack top down approach
+    bool subsetSum(vector<int>& nums, int sum)
+    {
+        // size = nums+1, sum+1
+        bool t[nums.size()+1][sum+1];
+        
+        for(int i= 0;i<=nums.size();i++)
+        {
+            t[i][0] = true;
+        }
+        
+        for(int i= 0;i<=sum;i++)
+        {
+            t[0][i] = false;
+        }
+        
+        t[0][0] = true;
+        
+        for(int i= 1;i<nums.size();i++)
+        {
+            for(int j=1;j<=sum;j++)
+            {
+                if(nums[i-1] <= j)
+                {
+                    //get max by including number in the subset || by not including in subset sum
+                    t[i][j] = t[i-1][j - nums[i-1]] || t[i-1][j];
+                }
+                else{
+                    t[i][j] = t[i-1][j];
+                }
+            }
+        }
+        return t[nums.size()-1][sum];
+    }
+    
+    bool canPartition(vector<int>& nums) {
+        
+        int n = nums.size();
+        
+        int sum = 0;
+        for(int  i = 0;i<n;i++)
+        {
+            sum+=nums[i];
+        }
+        
+        if(sum%2 != 0 )
+            return false;
+        
+        return subsetSum(nums, sum/2);
+        
+    }
+};

Diff for: README.md

@@ -83,7 +83,6 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | 56  | [Merge Intervals](https://leetcode.com/problems/merge-intervals) | [Python](./Python/56_MergeIntervals.py) | _O(nlogn)_ | _O(n)_ | Medium     | Intervals |      |
 | 697 | [Degree of an Array](https://leetcode.com/problems/degree-of-an-array) | [Java](./Java/Degree-of-an-Array)    | _O(n)_     | _O(n)_ | Easy       |  Array    |      |
 
-
 <br/>
 <div align="right">
     <b><a href="#algorithms">⬆️ Back to Top</a></b>
@@ -208,6 +207,20 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 <br/>
 
 
+## Dynamic Programming
+
+| #   | Title                                                                 | Solution                                  | Time   | Space  | Difficulty | Tag   | Note |
+ | --- | --------------------------------------------------------------------- | ----------------------------------------- | ------ | ------ | ---------- | ----- | ---- |
+| 416 | [ Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/)| [C++](./C++/Partition-Equal-Subset-Sum.cpp)| _O(n^2)_ | _O(n^2)_ | Medium  | DP |      |
+
+<br/>
+<div align="right">
+    <b><a href="#algorithms">⬆️ Back to Top</a></b>
+</div>
+<br/>
+
+
+
 ## Binary Search
 
 | #   | Title                                                                 | Solution                                                             | Time      | Space     | Difficulty | Tag | Note                   |