1800. Maximum Ascending Subarray Sum.md

1800. Maximum Ascending Subarray Sum

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the first one in Weekly Contest 233.

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Difficulty : Easy

Related Topics : Two Pointers

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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

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Solution

• mine
  • Java
    • Runtime: 0 ms, faster than 100.00%, Memory Usage: 36.4 MB, less than 100.00% of Java online submissions

      // O(N)time
      // O(1)space
      public int maxAscendingSum(int[] nums) {
          int res = nums[0];
          int t = nums[0];
          for(int i = 1; i  < nums.length; i++){
              if(nums[i] > nums[i - 1]){
                  t += nums[i];
              }else{
                  t = nums[i];
              }
              res = Math.max(res, t);
          }
          return res;
      }
      

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