1695. Maximum Erasure Value - kumaeki/LeetCode GitHub Wiki

1695. Maximum Erasure Value

You are given an array of positive integers nums and want to erase a subarray containing unique elements. The score you get by erasing the subarray is equal to the sum of its elements.

Return the maximum score you can get by erasing exactly one subarray.

An array b is called to be a subarray of a if it forms a contiguous subsequence of a, that is, if it is equal to a[l],a[l+1],...,a[r] for some (l,r).

Example 1:

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

Example 2:

Input: nums = [5,2,1,2,5,2,1,2,5]
Output: 8
Explanation: The optimal subarray here is [5,2,1] or [1,2,5].

Constraints:

  • 1 <= nums.length <= 10^5
  • 1 <= nums[i] <= 10^4

解法1

滑动窗口.

java

class Solution {
    public int maximumUniqueSubarray(int[] nums) {
        int len = nums.length;
        Set<Integer> set = new HashSet<Integer>();
        int left = 0, right = 0, res = 0, sum = 0;
        while(right < len){
            int numNew = nums[right++]; 
            while(set.contains(numNew)){
                int numOld = nums[left++]; 
                set.remove(numOld);
                sum -= numOld;
            }
            set.add(numNew);
            sum += numNew;
            res = Math.max(res, sum);
        }
        return res;
    }
}

C#

public class Solution {
    public int MaximumUniqueSubarray(int[] nums) {
        var len = nums.Length;
        var set = new HashSet<int>();
        var left = 0;
        var right = 0;
        var res = 0;
        var sum = 0;
        while(right < len){
            var numNew = nums[right++]; 
            while(set.Contains(numNew)){
                var numOld = nums[left++]; 
                set.Remove(numOld);
                sum -= numOld;
            }
            set.Add(numNew);
            sum += numNew;
            res = Math.Max(res, sum);
        }
        return res;
    }
}
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