# 665. Non-decreasing Array

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].

4 ，2，3

-1， 4 ，2，3

2，3，3， 2 ，4

``````class Solution {
public:
bool checkPossibility(vector<int>& nums) {
int cnt = 1, n = nums.size();
for (int i = 1; i < n; ++i) {
if (nums[i] < nums[i - 1]) {
if (cnt == 0) return false;
if (i == 1 || nums[i] >= nums[i - 2]) nums[i - 1] = nums[i];
else nums[i] = nums[i - 1];
--cnt;
}
}
return true;
}
};
``````

https://discuss.leetcode.com/topic/101144/java-c-simple-greedy-like-solution-with-explanation

LeetCode All in One 题目讲解汇总(持续更新中…)

 微信打赏 Venmo 打赏
（欢迎加入博主的知识星球，博主将及时答疑解惑，并分享刷题经验与总结，试运营期间前五十位可享受半价优惠～）

×

Help us with donation