ID NAME QUALITY USERS ACC % DIFFICULTY C I
18164 Atoms in the Lab   29 3551
8
5
328 Bishops   79 8154
14
6
2009 Cryptography   1 128
1
34
314 Digits of e   3 2917
1
1
24 Small factorials   148 38480
15
9
6236 Matches   7 432
27
8
36563 Hard Fibonacci   7 51
20
22
2906 GCD2   55 6115
12
11
2901 One Geometry Problem   9 1632
4
13
10676 0110SS   24 1676
13
9
54 Julka   156 18688
19
6
5699 The last digit re-visited   37 7192
9
9
3932 Point Connection Game in a Circle   3 707
13
21
3970 Convert to Decimal Base System   51
17
17
16034 Minimum Number   4 479
11
1
3023 Binary multiplication   3 224
17
17
35954 New Data Type   -1 108
5
5
18905 Kapti and Balu   1 34
17
17
8676 Digits of Phi (Golden Ratio)   2 288
17
17
270 Digits of Pi   12 5736
9
19
5294 Recurrence   2 251
28
17
29748 Robin Hood   27
1
1
3362 Setnja   2 233
9
17
10334 SOLDIERS   5 653
11
4
1423 Digits of SQRT(2)   6 2691
11
11
738 Another Counting Problem   219
71 Tree   2 409
12
9
1002 Uncle Jack   11 2890
9
8
235 Very Fast Multiplication   22 1005
26
22
6479 The Very Greatest Common Divisor   4 86
21
13
1475 Play with Digit Seven   4 99
30
13

#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