Codeforces Round 979 (Div. 2) |
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Finished |
This is the easy version of the problem. In this version, $$$n \leq 5000$$$. You can only make hacks if both versions of the problem are solved.
Orangutans are powerful beings—so powerful that they only need $$$1$$$ unit of time to destroy every vulnerable planet in the universe!
There are $$$n$$$ planets in the universe. Each planet has an interval of vulnerability $$$[l, r]$$$, during which it will be exposed to destruction by orangutans. Orangutans can also expand the interval of vulnerability of any planet by $$$1$$$ unit.
Specifically, suppose the expansion is performed on planet $$$p$$$ with interval of vulnerability $$$[l_p, r_p]$$$. Then, the resulting interval of vulnerability may be either $$$[l_p - 1, r_p]$$$ or $$$[l_p, r_p + 1]$$$.
Given a set of planets, orangutans can destroy all planets if the intervals of vulnerability of all planets in the set intersect at least one common point. Let the score of such a set denote the minimum number of expansions that must be performed.
Orangutans are interested in the sum of scores of all non-empty subsets of the planets in the universe. As the answer can be large, output it modulo $$$998\,244\,353$$$.
The first line contains an integer $$$t$$$ ($$$1 \leq t \leq 1000$$$) — the number of test cases.
The first line of each test case contains an integer $$$n$$$ ($$$1 \leq n \leq 5000$$$) — the number of planets in the universe.
The following $$$n$$$ lines contain two integers $$$l_i$$$ and $$$r_i$$$ ($$$1 \leq l_i \leq r_i \leq n$$$) — the initial interval of vulnerability of the $$$i$$$-th planet.
It is guaranteed that the sum of $$$n$$$ does not exceed $$$5000$$$ over all test cases.
For each test case, output an integer — the sum of scores to destroy all non-empty subsets of the planets in the universe, modulo $$$998\,244\,353$$$.
331 12 33 341 42 32 41 151 22 33 44 51 5
5 6 24
In the first testcase, there are seven non-empty subsets of planets we must consider:
The sum of scores of all non-empty subsets of the first testcase is $$$0 \cdot 4 + 1 \cdot 1 + 2\cdot2 = 5$$$.
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