README.md

1800. Maximum Ascending Subarray Sum

Given an array of positive integers nums, return the maximum possible sum of an ascending subarray in nums.

A subarray is defined as a contiguous sequence of numbers in an array.

A subarray [numsl, numsl+1, ..., numsr-1, numsr] is ascending if for all i where l <= i < r, numsi < numsi+1. Note that a subarray of size 1 is ascending.

Example 1:

Input: nums = [10,20,30,5,10,50]
Output: 65
Explanation: [5,10,50] is the ascending subarray with the maximum sum of 65.

Example 2:

Input: nums = [10,20,30,40,50]
Output: 150
Explanation: [10,20,30,40,50] is the ascending subarray with the maximum sum of 150.

Example 3:

Input: nums = [12,17,15,13,10,11,12]
Output: 33
Explanation: [10,11,12] is the ascending subarray with the maximum sum of 33.

Example 4:

Input: nums = [100,10,1]
Output: 100

Constraints:

• 1 <= nums.length <= 100
• 1 <= nums[i] <= 100

Solutions (Ruby)

1. Solution

# @param {Integer[]} nums
# @return {Integer}
def max_ascending_sum(nums)
  sum = nums[0]
  ret = sum

  (1...nums.size).each do |i|
    sum = nums[i] + (nums[i] > nums[i - 1] ? sum : 0)
    ret = [ret, sum].max
  end

  ret
end

Solutions (Rust)

1. Solution

impl Solution {
    pub fn max_ascending_sum(nums: Vec<i32>) -> i32 {
        let mut sum = nums[0];
        let mut ret = sum;

        for i in 1..nums.len() {
            if nums[i] > nums[i - 1] {
                sum += nums[i];
            } else {
                sum = nums[i];
            }
            ret = ret.max(sum);
        }

        ret
    }
}