ID NAME QUALITY USERS ACC % DIFFICULTY C I
18164 Atoms in the Lab   28 3201
7
5
328 Bishops   75 7665
14
6
2009 Cryptography   1 79
1
34
314 Digits of e   3 2835
1
1
24 Small factorials   129 33910
15
9
6236 Matches   6 421
28
6
36563 Hard Fibonacci   6 36
17
21
2906 GCD2   48 5659
12
10
2901 One Geometry Problem   8 1567
5
13
10676 0110SS   23 1611
13
9
54 Julka   137 16884
19
6
5699 The last digit re-visited   37 6908
9
9
16034 Minimum Number   4 461
11
1
35954 New Data Type   85
6
6
18905 Kapti and Balu   1 32
17
17
8676 Digits of Phi (Golden Ratio)   1 287
17
17
270 Digits of Pi   10 5576
9
16
5294 Recurrence   1 246
34
17
29748 Robin Hood   25
1
1
10334 SOLDIERS   5 619
11
4
1423 Digits of SQRT(2)   5 2623
13
13
738 Another Counting Problem   217
71 Tree   2 401
12
9
1002 Uncle Jack   10 2819
10
9
235 Very Fast Multiplication   18 911
27
22
6479 The Very Greatest Common Divisor   2 77
26
9
1475 Play with Digit Seven   4 77
17
9

#big-numbers

The problem involves arbitrary precision arithmetic

https://en.wikipedia.org/wiki/Arbitrary-precision_arithmetic https://en.wikipedia.org/wiki/Karatsuba_algorithm - efficient multiplication algorithm https://en.wikipedia.org/wiki/Toom%E2%80%93Cook_multiplication - as above https://en.wikipedia.org/wiki/Sch%C3%B6nhage%E2%80%93Strassen_algorithm - as above https://en.wikipedia.org/wiki/F%C3%BCrer%27s_algorithm - as above