<p>You are given an array of positive integers <code>nums</code> and want to erase a subarray containing&nbsp;<strong>unique elements</strong>. The <strong>score</strong> you get by erasing the subarray is equal to the <strong>sum</strong> of its elements.</p>

<p>Return <em>the <strong>maximum score</strong> you can get by erasing <strong>exactly one</strong> subarray.</em></p>

<p>An array <code>b</code> is called to be a <span class="tex-font-style-it">subarray</span> of <code>a</code> if it forms a contiguous subsequence of <code>a</code>, that is, if it is equal to <code>a[l],a[l+1],...,a[r]</code> for some <code>(l,r)</code>.</p>

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

<pre>
<strong>Input:</strong> nums = [4,2,4,5,6]
<strong>Output:</strong> 17
<strong>Explanation:</strong> The optimal subarray here is [2,4,5,6].
</pre>

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

<pre>
<strong>Input:</strong> nums = [5,2,1,2,5,2,1,2,5]
<strong>Output:</strong> 8
<strong>Explanation:</strong> The optimal subarray here is [5,2,1] or [1,2,5].
</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>
</ul>

class Solution {
public:
    // Find unique elements subarray with maximum sum
    // start - starting index of substring
    // end - ending index of substing
    int maximumUniqueSubarray(vector<int>& nums) {
        int n = nums.size();
        int maxScore = 0;

        vector<int> prefixSum(n, 0);
        prefixSum[0] = nums[0];
        for (int i = 1; i < n; i++) {
            prefixSum[i] = prefixSum[i - 1] + nums[i];
        }

        unordered_map<int, int> mp; // nums[i] -> index
        int start = 0;
        for (int end = 0; end < n; end++) {
            // Adjust start only if the duplicate element is within the current
            // window
            if (mp.find(nums[end]) != mp.end() && mp[nums[end]] >= start) {
                start = mp[nums[end]] + 1;
            }

            mp[nums[end]] = end;
            int sum = 0;
            if (start == 0) {
                sum = prefixSum[end];
            } else {
                sum = prefixSum[end] - prefixSum[start - 1];
            }
            maxScore = max(maxScore, sum);
        }

        return maxScore;
    }
};
107332