1695. Maximum Erasure Value

https://leetcode.com/problems/maximum-erasure-value/

Python

Two Pointers with Hashmap

(Catepillar Two Pointer, Same Direction Two Pointer)

• Time: O()
• Space: O()

class Solution:
    def maximumUniqueSubarray(self, nums: List[int]) -> int:
        seen = set()
        score, max_score = 0, 0
        start = 0

        for end in range(len(nums)):
            while nums[end] in seen:
                seen.remove(nums[start])
                score -= nums[start]
                start += 1

            score += nums[end]
            seen.add(nums[end])

            max_score = max(max_score, score)

        return max_score

Javascript

var maximumUniqueSubarray = function(nums) {
    let slow = 0;
    let fast = 0;
    const hashmap = new Map();
    let max = -1;
    let sum = 0;
    
    while (fast < nums.length) {
        sum += nums[fast];
        
        if (hashmap.has(nums[fast])) {
            max = Math.max(max, sum - nums[fast]);
            
            while (slow <= hashmap.get(nums[fast])) {
                sum -= nums[slow];
                slow++;
            }
            hashmap.delete(nums[fast]);
        }
        
        hashmap.set(nums[fast], fast);
        fast++;
    }
    
    max = Math.max(max, sum);
    return max;
};