<p>You are given a <strong>0-indexed</strong> integer array <code>nums</code>. You have to partition the array into one or more <strong>contiguous</strong> subarrays.</p>

<p>We call a partition of the array <strong>valid</strong> if each of the obtained subarrays satisfies <strong>one</strong> of the following conditions:</p>

<ol>
	<li>The subarray consists of <strong>exactly</strong> <code>2,</code> equal elements. For example, the subarray <code>[2,2]</code> is good.</li>
	<li>The subarray consists of <strong>exactly</strong> <code>3,</code> equal elements. For example, the subarray <code>[4,4,4]</code> is good.</li>
	<li>The subarray consists of <strong>exactly</strong> <code>3</code> consecutive increasing elements, that is, the difference between adjacent elements is <code>1</code>. For example, the subarray <code>[3,4,5]</code> is good, but the subarray <code>[1,3,5]</code> is not.</li>
</ol>

<p>Return <code>true</code><em> if the array has <strong>at least</strong> one valid partition</em>. Otherwise, return <code>false</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [4,4,4,5,6]
<strong>Output:</strong> true
<strong>Explanation:</strong> The array can be partitioned into the subarrays [4,4] and [4,5,6].
This partition is valid, so we return true.
</pre>

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

<pre>
<strong>Input:</strong> nums = [1,1,1,2]
<strong>Output:</strong> false
<strong>Explanation:</strong> There is no valid partition for this array.
</pre>

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

<ul>
	<li><code>2 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>6</sup></code></li>
</ul>

class Solution {
public:
    bool validPartition(vector<int>& nums) 
    {
        int n=nums.size();
        vector<bool> dp1(n,false);    
        vector<bool> dp2(n,false);    
        vector<bool> dp3(n,false);
        for(int i=0;i<n;i++)
        {
            if(i>=2)
            {
                if(nums[i]-nums[i-1]==1 and nums[i-1]-nums[i-2]==1)
                {
                    dp1[i-2]=true;
                }
                if(nums[i]==nums[i-1] and nums[i]==nums[i-2])
                {
                    dp2[i-2]=true;
                }
            }
            if(i>=1)
            {
                if(nums[i]==nums[i-1])
                {
                    dp3[i-1]=true;
                }
            }
        }    
        vector<bool> dp4(n+1,false);
        dp4[0]=true;
        for(int i=0;i<n;i++)
        {
            if(dp3[i] and dp4[i])dp4[i+2]=true;
            if((dp2[i] or dp1[i]) and dp4[i])dp4[i+3]=true;
        }
        // cout<<"dp2 dp3 dp4 "<<endl;
        // for(int i=0;i<n;i++)
        // {
        //     cout<<dp2[i]<<" "<<dp3[i]<<" "<<dp4[i]<<endl;
        // }
        return dp4[n];
    }
};
87300