P10588 "ALFR Round 2" D Hypercube.
Background
> What comes into view is a huge cherry blossom tree.
>
> Under the tree stands a girl, looking up at it.
> I think: She is probably a freshman. Maybe, like me, she also sneaked out.
> I also look up at that cherry blossom tree. The blurry colors of the blossoms cover the sky.
> A gust of wind rises, and the dancing cherry blossom petals wrap around the girl.
> The girl also sees me...
Description
That was your first encounter with Milja.
As always, Milja gives you another sequence problem.
The white envelope carries a scent of citrus,
and you carefully open it and read.
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In 3D, we have a cube.
The coordinates of its $2^3$ vertices can all be written in the form $(x,y,z)$.
Similarly, in $n$ dimensions, we have an $n$-dimensional hypercube with $2^n$ vertices.
Its edge length is $1$, and every coordinate of every vertex is a non-negative integer.
Starting from the point $(0,0,\dots,0)$, you walk along $m$ edges. Find the total number of ways to arrive at the point $(1,1,\dots,0)$.
Among the coordinates of the destination point, there are $l$ digits equal to $1$.
Since the answer may be very large, you only need to output the result modulo $998244353$.
Input Format
The first line contains an integer $T$, which denotes the number of test cases.
The next $T$ lines each contain three non-negative integers $n,m,l$.
Output Format
For each test case, output one line containing one integer: the answer.
Explanation/Hint
### Sample Explanation
The $7$ ways in the first example are:
- $(0,0,0) \to (1,0,0) \to (0,0,0) \to (1,0,0)$
- $(0,0,0) \to (0,1,0) \to (0,0,0) \to (1,0,0)$
- $(0,0,0) \to (0,0,1) \to (0,0,0) \to (1,0,0)$
- $(0,0,0) \to (1,0,0) \to (1,1,0) \to (1,0,0)$
- $(0,0,0) \to (1,0,0) \to (1,0,1) \to (1,0,0)$
- $(0,0,0) \to (0,1,0) \to (1,1,0) \to (1,0,0)$
- $(0,0,0) \to (0,0,1) \to (1,0,1) \to (1,0,0)$
### Constraints
| Subtask | Points | Constraints |
| :----------: | :----------: | :----------: |
| $0$ | $10$ | $\sum nm\le2^{26}$, $n\le2^{13}$ |
| $1$ | $20$ | $l=0$ |
| $2$ | $30$ | $\sum n^2\le2^{26}$ |
| $3$ | $40$ | - |
For $100\%$ of the testdata: $1\le T\le600$, $\sum n\log_2 n\le2^{25}$, $n\in[1,2^{21}]$, $m\in[0,2^{64}-1]$, $l\in[0,n]$.
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You turn to the back and find a line of small text:
Please do not forget to consider special cases.
Translated by ChatGPT 5