you have given N. you need to find out C(n,1*1)+C(n,2*2)+C(n,3*3)+c(n,4*4) + .....
Here c(n,r) = n!/((n-r)!*(r)!)
one way is find C(n,i*i) for all i between 1 <= i <= sqrt(n)
. Is there exist any efficient solution than this ??
# | User | Rating |
---|---|---|
1 | tourist | 4009 |
2 | jiangly | 3904 |
3 | Radewoosh | 3646 |
4 | jqdai0815 | 3620 |
4 | Benq | 3620 |
6 | orzdevinwang | 3529 |
7 | ecnerwala | 3494 |
8 | Um_nik | 3396 |
9 | gamegame | 3386 |
10 | maroonrk | 3350 |
# | User | Contrib. |
---|---|---|
1 | maomao90 | 164 |
1 | cry | 164 |
3 | Um_nik | 163 |
4 | atcoder_official | 159 |
5 | awoo | 158 |
6 | adamant | 157 |
7 | -is-this-fft- | 156 |
8 | nor | 154 |
9 | TheScrasse | 153 |
10 | Dominater069 | 152 |
Is there any efficient way to find out this ?
you have given N. you need to find out C(n,1*1)+C(n,2*2)+C(n,3*3)+c(n,4*4) + .....
Here c(n,r) = n!/((n-r)!*(r)!)
one way is find C(n,i*i) for all i between 1 <= i <= sqrt(n)
. Is there exist any efficient solution than this ??
Name |
---|