【leetcode】1051. Height Checker

题目如下：

Students are asked to stand in non-decreasing order of heights for an annual photo.

Return the minimum number of students not standing in the right positions.  (This is the number of students that must move in order for all students to be standing in non-decreasing order of height.)

 

Example 1:

Input: [1,1,4,2,1,3]
Output: 3
Explanation: 
Students with heights 4, 3 and the last 1 are not standing in the right positions.

 

Note:

1. 1 <= heights.length <= 100
2. 1 <= heights[i] <= 100

解题思路：本题要求的是有多少人没有站在正确的位置上，那么只要和正确的站位比较，看看有多少值对应不上即可。

代码如下：

class Solution(object):
    def heightChecker(self, heights):
        """
        :type heights: List[int]
        :rtype: int
        """
        sorted_heights = sorted(heights)
        res = 0
        for v1,v2 in zip(heights,sorted_heights):
            res += 1 if v1 != v2 else  0
        return res