2144 Maximum Difference Between Increasing Elements

Maximum Difference Between Increasing Elements

Given a 0-indexed integer array nums of size n, find the maximum difference between nums[i] and nums[j] (i.e., nums[j] - nums[i]), such that 0 <= i < j < n and nums[i] < nums[j].

Return *the maximum difference. *If no such i and j exists, return -1.

 

Example 1:

**Input:** nums = [7,**1**,**5**,4]
**Output:** 4
**Explanation:**
The maximum difference occurs with i = 1 and j = 2, nums[j] - nums[i] = 5 - 1 = 4.
Note that with i = 1 and j = 0, the difference nums[j] - nums[i] = 7 - 1 = 6, but i > j, so it is not valid.

Example 2:

**Input:** nums = [9,4,3,2]
**Output:** -1
**Explanation:**
There is no i and j such that i < j and nums[i] < nums[j].

Example 3:

**Input:** nums = [**1**,5,2,**10**]
**Output:** 9
**Explanation:**
The maximum difference occurs with i = 0 and j = 3, nums[j] - nums[i] = 10 - 1 = 9.

 

Constraints:

n == nums.length
2 <= n <= 1000
1 <= nums[i] <= 109

class Solution:
    def maximumDifference(self, nums: List[int]) -> int:
        min_arr =[]
        max_arr = []
        min_till_here = 10000000000
        max_till_here = 0
        for k in nums:
            min_till_here = min(k, min_till_here)
            min_arr.append(min_till_here)
            
        
        for k in nums[::-1]:
            max_till_here = max(k, max_till_here)
            max_arr.append(max_till_here)


        ans = -1
        for k1, k2 in zip(min_arr, max_arr[::-1]):
            if k2 > k1:
                ans = max(ans, k2-k1)
        return ans