[leetcode]581. Shortest Unsorted Continuous Subarray

Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order, too.

You need to find the shortest such subarray and output its length.

Example 1:

Input: [2, 6, 4, 8, 10, 9, 15]Output: 5Explanation: You need to sort [6, 4, 8, 10, 9] in ascending order to make the whole array sorted in ascending order.

Note:

1. Then length of the input array is in range [1, 10,000].
2. The input array may contain duplicates, so ascending order here means <=.

思路：copy一份原数组，对copy的数组排序， 再比较原数组和copy数组对应位置上的元素是否相等。

Solution:

package com.billkang;import java.util.Arrays;/** * @author binkang * @date May 20, 2017 */public class ShortestUnsortedContinuousSubarray {public int findUnsortedSubarray(int[] nums) {int n = nums.length;int[] temp = Arrays.copyOf(nums, n);Arrays.sort(temp);int start = 0;while (start < n && nums[start] == temp[start]) start++;int end = n - 1;while (end > start && nums[end] == temp[end]) end--;return end - start + 1;}}