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https://github.com/dlsniper/mul
Question from Slack channel
https://github.com/dlsniper/mul
Last synced: about 1 month ago
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Question from Slack channel
- Host: GitHub
- URL: https://github.com/dlsniper/mul
- Owner: dlsniper
- License: mit
- Created: 2016-02-25T19:30:41.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2016-02-25T20:19:42.000Z (over 8 years ago)
- Last Synced: 2024-06-20T11:12:02.144Z (5 months ago)
- Language: Go
- Size: 9.77 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# This is a problem from the Gopher Slack room
## Problem:
The four adjacent digits in the 1000-digit number that have the greatest product
are 9 × 9 × 8 × 9 = 5832.
The number is:
```
73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243
52584907711670556013604839586446706324415722155397
53697817977846174064955149290862569321978468622482
83972241375657056057490261407972968652414535100474
82166370484403199890008895243450658541227588666881
16427171479924442928230863465674813919123162824586
17866458359124566529476545682848912883142607690042
24219022671055626321111109370544217506941658960408
07198403850962455444362981230987879927244284909188
84580156166097919133875499200524063689912560717606
05886116467109405077541002256983155200055935729725
71636269561882670428252483600823257530420752963450
```
Find the thirteen adjacent digits in the 1000-digit number that have the greatest
product. What is the value of this product?
## Results
```
florin@sniper [09:10:45] [~/golang/src/github.com/dlsniper/mul/mul] [master]
-> % go test -bench=.
testing: warning: no tests to run
PASS
BenchmarkMul1-8 2000 684466 ns/op
BenchmarkMul2-8 5000 457176 ns/op
BenchmarkMul3-8 5000 212010 ns/op
BenchmarkMul4-8 10000 150611 ns/op
BenchmarkMul5-8 10000 153173 ns/op
BenchmarkMul6-8 3000 976646 ns/op
ok github.com/dlsniper/mul/mul 10.907s
```
```
florin@sniper [09:09:58] [~/golang/src/github.com/dlsniper/mul/mul] [master *]
-> % go test -benchmem -test.memprofilerate=1 -bench=.
testing: warning: no tests to run
PASS
BenchmarkMul1-8 2000 735461 ns/op 17335 B/op 5 allocs/op
BenchmarkMul2-8 3000 455565 ns/op 24584 B/op 2 allocs/op
BenchmarkMul3-8 5000 210202 ns/op 16384 B/op 1 allocs/op
BenchmarkMul4-8 10000 149474 ns/op 16384 B/op 1 allocs/op
BenchmarkMul5-8 10000 152326 ns/op 16384 B/op 1 allocs/op
BenchmarkMul6-8 2000 1764112 ns/op 26337 B/op 112 allocs/op
ok github.com/dlsniper/mul/mul 10.744s
```
## License
Original problem asked by [@mhatch](https://gophers.slack.com/team/mhatch). The code in `mul1` belongs to him.
The rest is under MIT.