10433: USACO 2024 January Contest, Gold Problem 3. Nap Sort
Description
Farmer John instructed some of the other cows in the farm to help Bessie with her task, but they are quite lazy, so Bessie uses that to her advantage. She divides the integers into two piles: Bessie pile and Helper pile. For every integer in Bessie's pile, she performs her algorithm as normal. For every integer in the helper pile, she assigns it to a different helper cow. Farmer John has a large farm, so Bessie can get as many helper cows as she wants. If a helper receives the integer $a_i$, Bessie instructs that cow to nap for $a_i$ seconds, and add their integer to the end of the array immediately when they wake up. If Bessie and a helper add an integer to the array at the same time, Bessie's integer will get added first since she is the leader. If more than one helper gets assigned the same integer, they will add copies of that integer to the array at the same time.
Help Bessie divide her integers so that the final array is sorted and the time it takes to sort the array is minimized.
Input
Each test case is formatted as follows:
The first line of each test case contains the number of integers $N$ in Bessie's array.
The next line of each test case contains $a_1, a_2, \dots, a_N$, the integers that Bessie is sorting. The same integer may appear multiple times.
It is guaranteed that the sum of $N$ over all tests does not exceed $2\cdot 10^5$.
Output
Sample 1 Input
4
5
1 2 4 5 100000000000
5
17 53 4 33 44
4
3 5 5 5
6
2 5 100 1 4 5
Sample 1 Output
6
15
5
6
Time | Event -----+---------------------- 1 | Helper adds 1 2 | Helper adds 2 3 | Bessie adds 4 5 | Bessie adds 5 6 | Bessie adds 10^{11}
In the second example, the best Bessie can do is sort everything by herself. One division that does *not* work is for Bessie to assign $4$ to a helper and the rest to herself because Bessie will end up adding $17$ to the array before the helper adds $4$ to the array.
In the third example, Bessie can assign all the integers to helpers.
In the fourth example, Bessie can assign $1,4,5$ to helpers and leave $2,5,100$ to herself.
Time | Event -----+------------------ 1 | Helper adds 1 3 | Bessie adds 2 4 | Helper adds 4 5 | Bessie adds 5 5 | Helper adds 5 6 | Bessie adds 100