maximum diff 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.
• https://leetcode.com/problems/maximum-difference-between-increasing-elements/description/

def maximumDifference(self, nums: List[int]) -> int:
	
	minVal = float('inf')
 
	diff = -1
	for n in nums:
		if n < minVal:
			minVal = min(n,minVal)
		else:
			currDiff = n - minVal
			if currDiff > 0:
				diff = max(diff, currDiff)
 
	return diff

trick

• track the smallest number, and if the number is STRICTLY greater than the smallest num then we get the difference