2016. 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.

class Solution {
public:
    int maximumDifference(vector<int>& nums) {
        int res = -1;
        for(int i = 0; i < nums.size(); i++) {
            for(int j = i + 1; j < nums.size(); j++) {
                if(nums[j] > nums[i]) res = max(res, nums[j] - nums[i]);
            }
        }
        return res;
    }
};