You are given an array of positive integers arr
. Perform some operations (possibly none) on arr
so that it satisfies these conditions:
- The value of the first element in
arr
must be1
. - The absolute difference between any 2 adjacent elements must be less than or equal to
1
. In other words,abs(arr[i] - arr[i - 1]) <= 1
for eachi
where1 <= i < arr.length
(0-indexed).abs(x)
is the absolute value ofx
.
There are 2 types of operations that you can perform any number of times:
- Decrease the value of any element of
arr
to a smaller positive integer. - Rearrange the elements of
arr
to be in any order.
Return the maximum possible value of an element in arr
after performing the operations to satisfy the conditions.
Input: arr = [2,2,1,2,1] Output: 2 Explanation: We can satisfy the conditions by rearranging arr so it becomes [1,2,2,2,1]. The largest element in arr is 2.
Input: arr = [100,1,1000] Output: 3 Explanation: One possible way to satisfy the conditions is by doing the following: 1. Rearrange arr so it becomes [1,100,1000]. 2. Decrease the value of the second element to 2. 3. Decrease the value of the third element to 3. Now arr = [1,2,3], which satisfies the conditions. The largest element in arr is 3.
Input: arr = [1,2,3,4,5] Output: 5 Explanation: The array already satisfies the conditions, and the largest element is 5.
1 <= arr.length <= 105
1 <= arr[i] <= 109
impl Solution {
pub fn maximum_element_after_decrementing_and_rearranging(arr: Vec<i32>) -> i32 {
let mut arr = arr;
arr.sort_unstable();
arr[0] = 1;
for i in 1..arr.len() {
arr[i] = arr[i].min(arr[i - 1] + 1);
}
*arr.last().unwrap()
}
}