<p>Given an integer array <code>nums</code>, return <code>true</code> <em>if you can partition the array into two subsets such that the sum of the elements in both subsets is equal or </em><code>false</code><em> otherwise</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,5,11,5]
<strong>Output:</strong> true
<strong>Explanation:</strong> The array can be partitioned as [1, 5, 5] and [11].
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [1,2,3,5]
<strong>Output:</strong> false
<strong>Explanation:</strong> The array cannot be partitioned into equal sum subsets.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 200</code></li>
	<li><code>1 &lt;= nums[i] &lt;= 100</code></li>
</ul>

map<pair<int,int>, bool> mp;
class Solution {
public:
    bool isPossiblePartition(vector<int>& nums) {
        int sum = 0;
        for(int i=0; i<nums.size(); i++) {
            sum += nums[i];
        }
        if(sum%2==0) {
            return true;
        }
        return false;
    }
    bool isSumPossible(vector<int>& nums, int targetSum, int idx) {
        if(targetSum == 0) {
            cout<<idx;
            return true;
        }
        if(idx >= nums.size() || targetSum < 0) {
            return false;
        }
        if(mp.find(make_pair(idx, targetSum)) != mp.end()) {
            return mp[make_pair(idx, targetSum)];
        }
        mp[make_pair(idx, targetSum)] = isSumPossible(nums, targetSum-nums[idx], idx+1) || isSumPossible(nums, targetSum, idx+1);
        return mp[make_pair(idx, targetSum)];
    }
    bool canPartition(vector<int>& nums) {
        if(!isPossiblePartition(nums)) {
            return false;
        }
        int sum = 0;
        for(int i=0; i<nums.size(); i++) {
            sum += nums[i];
        }
        sum = sum/2;
        //cout<<sum;
        mp.clear();
        sort(nums.begin(), nums.end());

        return isSumPossible(nums, sum, 0);
        //return false;
    }
};
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