<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>

class Solution {
public:
    bool findTheAns(vector<int>&nums,int sum,int index, map<pair<int,int>,int>& dp){
        if(index==nums.size()){
            if(sum==0){
                return true;
            }
            return false;
        }
        if(dp.find({index,sum})!=dp.end()){
            return dp[{index,sum}];
        }
        int ans=0;
        if(nums[index]<=sum){
            ans=ans||findTheAns(nums,sum-nums[index],index+1,dp);
        }
        dp[{index,sum}]=ans||findTheAns(nums,sum,index+1,dp); 
        return dp[{index,sum}];
    }
    bool canPartition(vector<int>& nums) {
        int sum=0;
         map<pair<int,int>,int> dp;
        for(int i=0;i<nums.size();i++){
            sum+=nums[i];
        }
        if(sum&1){
            return false;
        }
        int index=0;
        bool ans=findTheAns(nums,sum/2,index,dp);
        return ans;
    }
};
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