1051. 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.
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

这题没什么好说的，理解了题意之后，就行了。

class HeightChecker : public Solution {
public:
    void Exec() {

    }
    int heightChecker(vector<int>& heights) {
        vector<int> sorted = heights;
        std::sort(sorted.begin(), sorted.end());

        int res = 0;
        for (int i = 0; i < heights.size(); i++) {
            if (sorted[i] != heights[i]) {
                ++res;
            }
        }
        return res;
    }
};