README_EN.md

1800. Maximum Ascending Subarray Sum

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Description

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.

 

Constraints:

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

Solutions

Python3

class Solution:
    def maxAscendingSum(self, nums: List[int]) -> int:
        ans = t = 0
        for i, v in enumerate(nums):
            if i == 0 or v > nums[i - 1]:
                t += v
                ans = max(ans, t)
            else:
                t = v
        return ans

Java

class Solution {
    public int maxAscendingSum(int[] nums) {
        int ans = 0, t = 0;
        for (int i = 0; i < nums.length; ++i) {
            if (i == 0 || nums[i] > nums[i - 1]) {
                t += nums[i];
                ans = Math.max(ans, t);
            } else {
                t = nums[i];
            }
        }
        return ans;
    }
}

C++

class Solution {
public:
    int maxAscendingSum(vector<int>& nums) {
        int ans = 0, t = 0;
        for (int i = 0; i < nums.size(); ++i) {
            if (i == 0 || nums[i] > nums[i - 1]) {
                t += nums[i];
                ans = max(ans, t);
            } else {
                t = nums[i];
            }
        }
        return ans;
    }
};

Go

func maxAscendingSum(nums []int) int {
	ans, t := 0, 0
	for i, v := range nums {
		if i == 0 || v > nums[i-1] {
			t += v
			if ans < t {
				ans = t
			}
		} else {
			t = v
		}
	}
	return ans
}

C

#define max(a,b) (((a) > (b)) ? (a) : (b))

int maxAscendingSum(int* nums, int numsSize){
    int res = nums[0];
    int sum = nums[0];
    for (int i = 1; i < numsSize; i++) {
        if (nums[i - 1] >= nums[i]) {
            res = max(res, sum);
            sum = 0;
        }
        sum += nums[i];
    }
    return max(res, sum);
}

TypeScript

function maxAscendingSum(nums: number[]): number {
    const n = nums.length;
    let res = nums[0];
    let sum = nums[0];
    for (let i = 1; i < n; i++) {
        if (nums[i] <= nums[i - 1]) {
            res = Math.max(res, sum);
            sum = 0;
        }
        sum += nums[i];
    }
    return Math.max(res, sum);
}

Rust

impl Solution {
    pub fn max_ascending_sum(nums: Vec<i32>) -> i32 {
        let n = nums.len();
        let mut res = nums[0];
        let mut sum = nums[0];
        for i in 1..n {
            if nums[i - 1] >= nums[i] {
                res = res.max(sum);
                sum = 0;
            }
            sum += nums[i];
        }
        res.max(sum)
    }
}

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