Can anyone plz help me with this problem?Problem
# | User | Rating |
---|---|---|
1 | ecnerwala | 3648 |
2 | Benq | 3580 |
3 | orzdevinwang | 3570 |
4 | cnnfls_csy | 3569 |
5 | Geothermal | 3568 |
6 | tourist | 3565 |
7 | maroonrk | 3530 |
8 | Radewoosh | 3520 |
9 | Um_nik | 3481 |
10 | jiangly | 3467 |
# | User | Contrib. |
---|---|---|
1 | maomao90 | 174 |
2 | adamant | 164 |
2 | awoo | 164 |
4 | TheScrasse | 160 |
5 | nor | 159 |
6 | maroonrk | 156 |
7 | -is-this-fft- | 150 |
8 | SecondThread | 148 |
9 | pajenegod | 145 |
9 | orz | 145 |
Name |
---|
Just precalculate all factorials in the range [0, 107] modulo 1000000000000037.
Then the rest is just range sum.
Edit. I tried it out. The answer is correct. But I didn't notice the memory limit (This solution will get MLE). Sorry.
Lets solve it offline. There are maximum 2*n different numbers. Calculate factorial only for this numbers. Notice that, when we multiplying the big numbers, there can exists number that > 1023. So use binary multiplying.
You can use 1000-ary multiplication as given (mod = 10 ^15) * 10 ^ 3 < MAX_LONG_INT. It will cost maximum of only 3 operations reducing the log(n) factor.