<p>You are given an integer array <code>nums</code>. You want to maximize the number of points you get by performing the following operation any number of times:</p>

<ul>
	<li>Pick any <code>nums[i]</code> and delete it to earn <code>nums[i]</code> points. Afterwards, you must delete <b>every</b> element equal to <code>nums[i] - 1</code> and <strong>every</strong> element equal to <code>nums[i] + 1</code>.</li>
</ul>

<p>Return <em>the <strong>maximum number of points</strong> you can earn by applying the above operation some number of times</em>.</p>

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

<pre>
<strong>Input:</strong> nums = [3,4,2]
<strong>Output:</strong> 6
<strong>Explanation:</strong> You can perform the following operations:
- Delete 4 to earn 4 points. Consequently, 3 is also deleted. nums = [2].
- Delete 2 to earn 2 points. nums = [].
You earn a total of 6 points.
</pre>

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

<pre>
<strong>Input:</strong> nums = [2,2,3,3,3,4]
<strong>Output:</strong> 9
<strong>Explanation:</strong> You can perform the following operations:
- Delete a 3 to earn 3 points. All 2&#39;s and 4&#39;s are also deleted. nums = [3,3].
- Delete a 3 again to earn 3 points. nums = [3].
- Delete a 3 once more to earn 3 points. nums = [].
You earn a total of 9 points.</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 2 * 10<sup>4</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
</ul>

#include<bits/stdc++.h>
using namespace std;
class Solution {
public:
    int solve(int num,unordered_map<int, int> &mpp,vector<int>&dp) {
    
    if (num <= 0) return 0;
    if(dp[num]!=-1)return dp[num];
    
    // Option 1: Skip the current number 'num'
    int skip = solve(num - 1,mpp,dp);
    
    // Option 2: Take the current number 'num', earn points, and skip 'num-1'
    int take = num * mpp[num] + solve(num - 2,mpp,dp);
    
    // Return the maximum of both options
    return dp[num]=max(skip, take);
}

    int deleteAndEarn(vector<int>& nums) {
        int max_num = 0;
        int n=nums.size();
   
    sort(nums.begin(),nums.end());
    // Fill the frequency map
    unordered_map<int, int> mpp;
    for (int i = 0; i < n; ++i) {
       
        mpp[nums[i]]++;
        max_num = max(max_num, nums[i]);
    }
     vector<int>dp(max_num+1,-1);
    
    // Solve the problem starting from the largest number in the list
    return solve(max_num,mpp,dp) ;
    
    return 0;
        
    }
};
19283