ID NAME QUALITY USERS ACC % DIFFICULTY C I
18164 Atoms in the Lab   32 3821
8
5
328 Bishops   83 8947
14
7
2009 Cryptography   1 142
1
34
314 Digits of e   5 3015
3
3
24 Small factorials   154 50343
15
9
6236 Matches   8 451
26
7
36563 Hard Fibonacci   7 86
20
21
2906 GCD2   60 6815
12
11
2901 One Geometry Problem   9 1816
4
13
10676 0110SS   26 1757
13
9
54 Julka   163 23162
19
6
5699 The last digit re-visited   39 7450
9
9
27068 Leaf   1 66
9
1
3932 Point Connection Game in a Circle   3 755
13
21
3970 Convert to Decimal Base System   53
17
17
16034 Minimum Number   5 491
11
1
3023 Binary multiplication   3 226
17
17
35954 New Data Type   1 120
6
6
18905 Kapti and Balu   1 38
17
17
8676 Digits of Phi (Golden Ratio)   2 293
17
17
270 Digits of Pi   13 5894
9
19
5294 Recurrence   2 255
28
17
29748 Robin Hood   31
1
1
3362 Setnja   2 243
9
17
10334 SOLDIERS   7 749
8
8
1423 Digits of SQRT(2)   6 2747
11
11
738 Another Counting Problem   1 226
1
1
71 Tree   3 451
12
9
1002 Uncle Jack   13 2964
9
8
235 Very Fast Multiplication   24 1286
26
22
6479 The Very Greatest Common Divisor   4 93
21
13
1475 Play with Digit Seven   3 126
34
14

#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