<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>

#include <bits/stdc++.h>
#define ss second
#define ff first
#define pii pair<int,int>
#define pb push_back
#define ll int
#define vll vector<ll>	
#define pll pair<ll,ll>
#define ld long double
#define all(x) x.begin(),x.end()

class Solution {
public:

    struct h_ {
    size_t operator()(const pair<ll, ll>& p) const {
        size_t seed = 0;
        hash<ll> ll_hash;
         hash<ll> ll_hash1;
        seed ^= ll_hash(p.ff) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        seed ^= ll_hash(p.ss) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
        
        return seed;
        }
    };

    unordered_map<pll,ll,h_> memo;
    ll foo(ll pos,ll prev_ele,vector<int>& arr1 ,vector<int> & arr2){
        
        ll n = arr1.size();
        if(pos>n)return 0;


        if(memo.count({pos,prev_ele}))return memo[{pos,prev_ele}];
        if(arr1[pos-1]>prev_ele){
            auto it=upper_bound(all(arr2),prev_ele);
            ll bigger_exists=it!=arr2.end();
            return  memo[{pos,prev_ele}] = min(foo(pos+1,arr1[pos-1],arr1,arr2), (!bigger_exists) ? (ll)1e9 : (1+foo(pos+1,*it,arr1,arr2)) );
        }
        else{
             auto it=upper_bound(all(arr2),prev_ele);
                ll bigger_exists=it!=arr2.end();
                if(!bigger_exists) return memo[{pos,prev_ele}] = 1e9;
                else return memo[{pos,prev_ele}] = 1+foo(pos+1,*it,arr1,arr2);
        }
    }
    int makeArrayIncreasing(vector<int>& arr1, vector<int>& arr2) {

        ll n=arr1.size();
        sort(all(arr2));

        memo.clear();
        ll res=foo(1,-1e9,arr1,arr2);
        if(res>=1e9)return -1;
        else return res;
        //:) me
        // vector<int> arr1_=arr1;
        // arr1_[0]=arr2[0];
        // memo.clear();
        // // ll alter_start=foo(2,arr1_[0],arr1_,arr2);

        // if(res>=1e9 && 1+alter_start>=1e9)return -1;
        // if(res<1+alter_start)return res;
        // else return 1+alter_start;

    }
};




























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