Count Heights Away From Their Sorted Positions

### Problem Let expected be the heights sorted into nondecreasing order. Return the number of positions i where the current `heights[i]` differs from expected[i]. Equal-height students are indistinguishable for this comparison. ```cpp class Solution { public: int heightChecker(vector<int>& heights); }; ``` ### Examples **Example 1:** ```text Input: heights = [3,1,2,2] Output: 3 Explanation: Expected is[1,2,2,3]; positions0,1,3 differ. ``` **Example 2:** ```text Input: heights = [2,2,4] Output: 0 Explanation: The current array is already nondecreasing. ``` ### Constraints - The line contains 1 to 100 students. - Every supplied height is an integer in `[1,100]`. ### Contract considerations Compare numeric heights at each index; identities among equal heights do not matter. ```hint Read the boundary condition If equal-height students exchange identities, should a position whose numeric height already matches still count? ``` ### Boundary reminders Compare numeric heights at each index; identities among equal heights do not matter.