Force deduction solution summary 1051 height checker

Directory links ：

Force buckle programming problem - The solution sums up _ Share + Record -CSDN Blog

GitHub Synchronous question brushing items ：

https://github.com/September26/java-algorithms

Original link ： Power button

describe ：

The school plans to take an annual commemorative photo for all the students . According to the requirements , Students need to follow The decreasing Line up in order of height .

The sorted height is an integer array expected Express , among expected[i] It's expected to be number... In this line i The height of a student （ Subscript from 0 Start ）.

Give you an array of integers heights , Express Current student position The height of .heights[i] It's the... In this line i The height of a student （ Subscript from 0 Start ）.

Return to satisfaction heights[i] != expected[i] Of Subscript quantity .

Example ：

Input ：heights = [1,1,4,2,1,3]
Output ：3 
explain ：
Height ：[1,1,4,2,1,3]
expect ：[1,1,1,2,3,4]
Subscript 2 、4 、5 The height of the students at does not match .
Example 2：

Input ：heights = [5,1,2,3,4]
Output ：5
explain ：
Height ：[5,1,2,3,4]
expect ：[1,2,3,4,5]
The corresponding student heights of all subscripts do not match .
Example 3：

Input ：heights = [1,2,3,4,5]
Output ：0
explain ：
Height ：[1,2,3,4,5]
expect ：[1,2,3,4,5]
The corresponding student heights of all subscripts match .
 

Tips ：

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

source ： Power button （LeetCode）
link ：https://leetcode.cn/problems/height-checker
Copyright belongs to the network . For commercial reprint, please contact the official authority , Non-commercial reprint please indicate the source .

Their thinking ：

*  Their thinking ：
*  Sort array after copying , Then compare the different quantity with the original array .
* <p>

Code ：

public int heightChecker(int[] heights) {
        int[] copy = new int[heights.length];
        System.arraycopy(heights, 0, copy, 0, heights.length);
        Arrays.sort(copy);
        int sum = 0;
        for (int i = 0; i < heights.length; i++) {
            int height1 = heights[i];
            int height2 = copy[i];
            if (height1 != height2) {
                sum++;
            }
        }
        return sum;
    }