1051. Height Checker.cpp

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.
Example 2:

Input: heights = [5,1,2,3,4]
Output: 5
Example 3:

Input: heights = [1,2,3,4,5]
Output: 0


Constraints:

1 <= heights.length <= 100
1 <= heights[i] <= 100







class Solution {
public:
    int heightChecker(vector<int>& heights) {
        int n=heights.size();
        vector<int> target(n);

        for(int i=0;i<n;i++)
            target[i]=heights[i];

        sort(target.begin(), target.end());

        int cnt=0;

        for(int i=0;i<n;i++){
            if(heights[i]!=target[i])
                cnt++;
        }
        return cnt;
    }
};