<p>You are given an integer array <code>nums</code> and an integer <code>x</code>. In one operation, you can either remove the leftmost or the rightmost element from the array <code>nums</code> and subtract its value from <code>x</code>. Note that this <strong>modifies</strong> the array for future operations.</p>

<p>Return <em>the <strong>minimum number</strong> of operations to reduce </em><code>x</code> <em>to <strong>exactly</strong></em> <code>0</code> <em>if it is possible</em><em>, otherwise, return </em><code>-1</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [1,1,4,2,3], x = 5
<strong>Output:</strong> 2
<strong>Explanation:</strong> The optimal solution is to remove the last two elements to reduce x to zero.
</pre>

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

<pre>
<strong>Input:</strong> nums = [5,6,7,8,9], x = 4
<strong>Output:</strong> -1
</pre>

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

<pre>
<strong>Input:</strong> nums = [3,2,20,1,1,3], x = 10
<strong>Output:</strong> 5
<strong>Explanation:</strong> The optimal solution is to remove the last three elements and the first two elements (5 operations in total) to reduce x to zero.
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= x &lt;= 10<sup>9</sup></code></li>
</ul>

class Solution {
public:
    int minOperations(vector<int>& nums, int x) {
        vector<int>pref;
        vector<int>suff;
        int sum=0;
        for(int i=0;i<nums.size();i++){
            sum=sum+nums[i];
            pref.push_back(sum);
        }
        sum=0;
        int n=nums.size();
        for(int i=nums.size()-1;i>=0;i--){
           sum=sum+nums[i];
           suff.push_back(sum);
        }
        int ans=1e9;
        for(int i=0;i<nums.size();i++){
            int y=x-pref[i];
            cout<<y<<" ";
            if(y==0){
                ans=min(ans,i+1);
                continue;
            }
            if(y<0){
                break;
            }
            int index=lower_bound(suff.begin(),suff.end(),y)-suff.begin();
            cout<<index<<" ";
            if(index<0){
                break;
            }
            if(index+i+2>=n){
                continue;
            }
            if(suff[index]==y){
                ans=min(ans,i+1+index+1);
            }
        }
        for(int i=0;i<nums.size();i++){
            int y=x-suff[i];
            if(y==0){
                ans=min(ans,i+1);
            }
            if(y<0){
                break;
            }
            int index=lower_bound(pref.begin(),pref.end(),y)-pref.begin();
            if(index<0){
                break;
            }
            if(index+i+2>=n){
                continue;
            }
            if(pref[index]==y){
                ans=min(ans,i+1+index+1);
            }
        }
        if(ans==1e9){
            return -1;
        }
        return ans;
    }
};
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