<p>Given two integer arrays&nbsp;<code>arr1</code> and <code>arr2</code>, return the minimum number of operations (possibly zero) needed&nbsp;to make <code>arr1</code> strictly increasing.</p>

<p>In one operation, you can choose two indices&nbsp;<code>0 &lt;=&nbsp;i &lt; arr1.length</code>&nbsp;and&nbsp;<code>0 &lt;= j &lt; arr2.length</code>&nbsp;and do the assignment&nbsp;<code>arr1[i] = arr2[j]</code>.</p>

<p>If there is no way to make&nbsp;<code>arr1</code>&nbsp;strictly increasing,&nbsp;return&nbsp;<code>-1</code>.</p>

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

<pre>
<strong>Input:</strong> arr1 = [1,5,3,6,7], arr2 = [1,3,2,4]
<strong>Output:</strong> 1
<strong>Explanation:</strong> Replace <code>5</code> with <code>2</code>, then <code>arr1 = [1, 2, 3, 6, 7]</code>.
</pre>

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

<pre>
<strong>Input:</strong> arr1 = [1,5,3,6,7], arr2 = [4,3,1]
<strong>Output:</strong> 2
<strong>Explanation:</strong> Replace <code>5</code> with <code>3</code> and then replace <code>3</code> with <code>4</code>. <code>arr1 = [1, 3, 4, 6, 7]</code>.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> arr1 = [1,5,3,6,7], arr2 = [1,6,3,3]
<strong>Output:</strong> -1
<strong>Explanation:</strong> You can&#39;t make <code>arr1</code> strictly increasing.</pre>

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

<ul>
	<li><code>1 &lt;= arr1.length, arr2.length &lt;= 2000</code></li>
	<li><code>0 &lt;= arr1[i], arr2[i] &lt;= 10^9</code></li>
</ul>

<p>&nbsp;</p>

class Solution {
public:
    int dp[2002][2002];

    int getMinOper(vector<int>&arr1,vector<int>&arr2,int last=-1,int idx=0)
    {
        if(idx==arr1.size())
            return 0;

        if(dp[last+1][idx]!=-1)
            return dp[last+1][idx];

        if(idx==0)
        {
            int keepValueSame = getMinOper(arr1,arr2,-1,idx+1);
            int changeValue = 1+getMinOper(arr1,arr2,0,idx+1);

            return dp[last+1][idx] = min(keepValueSame,changeValue);
        }
        else
        {
            int lastValue = (last==-1) ? arr1[idx-1] : arr2[last];
            int keepValueSame = 10000000 , changeValue = 10000000;

            if(arr1[idx] > lastValue)
                keepValueSame = getMinOper(arr1,arr2,-1,idx+1);

            auto it = upper_bound(arr2.begin(),arr2.end(),lastValue);
            if(it!=arr2.end())
                changeValue = 1+getMinOper(arr1,arr2,it-arr2.begin(),idx+1);

            return dp[last+1][idx] = min(keepValueSame,changeValue);
        }

        return dp[last+1][idx] = 10000000;
    }

    int makeArrayIncreasing(vector<int>& arr1, vector<int>& arr2) {
        sort(arr2.begin(),arr2.end());
        memset(dp,-1,sizeof dp);

        int ans = getMinOper(arr1,arr2);

        if(ans==10000000)
            ans=-1;

        return ans;
    }
};
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