https://leetcode.com/problems/height-checker/
Students are asked to stand in non-decreasing order of heights for an annual photo.
Return the minimum number of students that must move in order for all students to be standing in non-decreasing order of height.
Notice that when a group of students is selected they can reorder in any possible way between themselves and the non selected students remain on their seats.
Example 1:
Input: heights = [1,1,4,2,1,3] Output: 3 Explanation: Current array : [1,1,4,2,1,3] Target array : [1,1,1,2,3,4] On index 2 (0-based) we have 4 vs 1 so we have to move this student. On index 4 (0-based) we have 1 vs 3 so we have to move this student. On index 5 (0-based) we have 3 vs 4 so we have to move this student.