Description
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].
Tags: Array
思路
题目要求判断所给数组能否能通过最多一次的修改，变为递增数组。
Java:
public boolean checkPossibility(int[] nums) {
if (nums.length < 3) {
return true;
}
int modifyCount = 0;
if (nums[0] > nums[1]) {
modifyCount++;
nums[0] = nums[1];
}
for (int i = 1; i < nums.length && modifyCount < 2; i++) {
if (nums[i] < nums[i-1]) {
if (nums[i] > nums[i-2]) {
nums[i-1] = nums[i-2];
} else {
nums[i] = nums[i-1];
}
modifyCount++;
}
}
return modifyCount < 2;
}
结语
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