Can anyone please provide any hint for this problem? Throwing Dice
# | User | Rating |
---|---|---|
1 | ecnerwala | 3650 |
2 | Benq | 3582 |
3 | Geothermal | 3570 |
3 | orzdevinwang | 3570 |
5 | cnnfls_csy | 3569 |
6 | tourist | 3565 |
7 | maroonrk | 3532 |
8 | Radewoosh | 3522 |
9 | Um_nik | 3483 |
10 | jiangly | 3468 |
# | User | Contrib. |
---|---|---|
1 | maomao90 | 174 |
2 | awoo | 164 |
3 | adamant | 163 |
4 | TheScrasse | 159 |
5 | nor | 158 |
6 | maroonrk | 156 |
7 | -is-this-fft- | 151 |
8 | SecondThread | 147 |
9 | orz | 146 |
10 | pajenegod | 145 |
Can anyone please provide any hint for this problem? Throwing Dice
Name |
---|
Let f(n) be the number of ways of throwing dices to get a sum of n, Then consider the last dice throw. It has 6 possibilities 1-6. So f(n) = f(n-1) + f(n-2) + ... + f(n-6).
The recurrence is correct. However, unfortunately, it TLE's. There is hope though. This is a linear recurrence can be computed for arbitrary values of n using fast matrix exponentiation. Here is a geeks for geeks article that illustrates the technique in action https://www.geeksforgeeks.org/find-nth-term-a-matrix-exponentiation-example/
My fav trick in such problems:
1. precalc first 20 values
2. use Berlekamp-Massey algorihm to compute n_th value of Linear recurrence
source: https://codeforces.com/blog/entry/61306?
another problems:
https://codeforces.com/contest/392/submission/51596991
https://codeforces.com/contest/678/submission/51597127