Non-decreasing Array

最新推荐文章于 2021-09-13 18:57:32 发布

转载最新推荐文章于 2021-09-13 18:57:32 发布 · 85 阅读

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原文链接：http://www.cnblogs.com/beiyeqingteng/p/10789824.html

本文介绍了一个算法问题，即判断一个整数数组通过修改最多一个元素是否可以变成非递减序列。通过示例解释了算法的实现，包括输入为[4,2,3]返回真，因为可以通过修改第一个4到1来获得非递减数组；而输入为[4,2,1]返回假，因为无法通过修改最多一个元素得到非递减数组。

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Given an array with n integers, your task is to check if it could become non-decreasing by modifying at most 1 element.

We define an array is non-decreasing if array[i] <= array[i + 1] holds for every i (1 <= i < n).

Example 1:

Input: [4,2,3]
Output: True
Explanation: You could modify the first 4 to 1 to get a non-decreasing array.

Example 2:

Input: [4,2,1]
Output: False
Explanation: You can't get a non-decreasing array by modify at most one element.

Note: The n belongs to [1, 10,000].

 1 public boolean checkPossibility(int[] nums) {
 2         int cnt = 0;                                                                    //the number of changes
 3         for(int i = 1; i < nums.length && cnt<=1 ; i++){
 4             if(nums[i-1] > nums[i]){
 5                 cnt++;
 6                 if(i-2<0 || nums[i-2] <= nums[i])nums[i-1] = nums[i];                    //modify nums[i-1] of a priority
 7                 else nums[i] = nums[i-1];                                                //have to modify nums[i]
 8             }
 9         }
10         return cnt<=1; 
11     }

转载于:https://www.cnblogs.com/beiyeqingteng/p/10789824.html