<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[2000][2005];

    int solve(int i,int j, int n, int m,vector<int>&a, vector<int>&b){
        if(i==n) return 0;
        if(dp[i][j]!=-1) return dp[i][j];
        int ans=1e9;

        if(j==0){
            if(i==0 || a[i]>a[i-1]) ans=min(ans,solve(i+1,0,n,m,a,b));
            int chk=-2;
            if(i) chk=a[i-1];
            int ind=upper_bound(b.begin(),b.end(),chk)-b.begin();
            if(ind!=m) ans=min(ans,1+solve(i+1,ind+1,n,m,a,b));
        }
        else{
            
            if(a[i]>b[j-1]) ans=min(ans,solve(i+1,0,n,m,a,b));
            int ind=upper_bound(b.begin(),b.end(),b[j-1])-b.begin();
            if(ind!=m) ans=min(ans,1+solve(i+1,ind+1,n,m,a,b));
        }

        return dp[i][j]=ans;
    }
    
    int makeArrayIncreasing(vector<int>& a, vector<int>& b) {
        sort(b.begin(),b.end());
        b.erase(unique(b.begin(),b.end()),b.end());
       // cout<<b.size()<<endl;
       int n=a.size(),m=b.size();
        memset(dp,-1,sizeof(dp));
       int ans= solve(0,0,n,m,a,b);
       if(ans==1e9) return -1;
       return ans;
        //return 1;
    }
};
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