4 ms·

Thanks for the shout-out! If you can't remember the long URL, http://algorithms.wtf http://algorithms.wtf also works. Please send me bug reports!

0xmohit 10y ago
Thanks. Easy to remember domain :)
Jun8 10y ago
Looks great, thanks a lot! While causally browsing I noted the following in the 8-queens backtracking example: "The following recursive algorithm, essentially due to Gauss (who called it “methodical groping”), ..." Hilarious, especially given the current situation. I'd like to know what his original German term was.
- ludwigschubert 10y ago
  Oh this is a fun rabbit hole to go down: Gauss indeed wrote "methodisches tatonniren"[1], the latter of which is not a common German word, nor does it suggest grouping. I believe it to be an expression used at the time which was borrowed from French "tâtonner", which means "fumble", to describe a step-by-step process, "approaching" a solution. The closest I get in modern German is "herantasten", which in turn does not have an elegant English translation; you will have to take its elements "heran" (onto) and "tasten" (touch/feel/grope) individually to judge how close it is to fumble. So, methodical groping is not as far off as you might have thought! [1] https://books.google.com/books?id=3jEDAAAAQAAJ&pg=RA1-PA106&lpg=RA1-PA106&dq=8+königinnen+gauss&source=bl&ots=BuaJSJydKs&sig=1Z78TngV_y6IyQ8QNRwSVmvohvY&hl=en&sa=X&ved=0ahUKEwim0v3zhZHQAhXolFQKHStQCFYQ6AEIIjAB#v=onepage&q&f=true https://books.google.com/books?id=3jEDAAAAQAAJ&pg=RA1-PA106&... This may be a typo—the regular verb form would be "tatonnieren"—then again a lot of German spelling has changed since the time of those letters.
  - bonzini 10y ago
    The word "tâtonner" should be the same as Italian "procedere (proceed) a tastoni", since usually the circumflex accent in French correspond to an "s" in Italian. The meaning is "feel your way"---proceed carefully and at every step feel what is around you, as if you were walking on complete darkness.
    - scns 10y ago
      >proceed carefully and at every step feel what is around you, as if you were walking on complete darkness. this would be a fitting translation of the german word "herantasten", which has nothing to do with groping btw
      - bonzini 10y ago
        Yup, "groping around" is not at all the same as "groping"!!!
mrkgnao 10y ago
TIL there is a .wtf TLD.
- 0xmohit 10y ago
  There's also a .study TLD. And algorithms.study is available!
misoukrane 10y ago
Thanks for making the resources free.
- ambar123 10y ago
  What resource bro...
graycat 10y ago
Thanks. Given a directed graph with on each arc a maximum flow and a cost per unit of flow, how to find the least cost flows for a given total flow? That is linear programming. The simplex algorithm takes on a special form, and a simplex basic solution corresponds to a spanning tree. A simplex pivot is adding an arc to the tree to yield a circuit, and getting the cost of sending a unit of flow around the circuit evaluates that new arc. Etc. W. Cunningham defined a strongly feasible basic solution which avoids cycling. IIRC, D. Bertsekas has a good (polynomial) algorithm for that problem. I didn't see such mentioned in your table of contents. On my 14" screen, your PDF files would be much easier to read if the maximum number of characters per line was about 50.
deleted 10y ago
[deleted]
skiplist1 10y ago
I just skimmed over skiplist in point 10 of your book. The concept and definition of skiplist is easy to grok and it is well explained but in point 10 there is not any information as to when should I use a skiplist, what kind of problem a skiplist is a good tool to use. I have bookmarked your page, it seems to be a useful resource if it is complemented with a comparison and use case for all these data structures.
- sobani 10y ago
  A skiplist is a good candidate for problems where you are considering some kind of self-balancing tree. I find a skiplist to be the simpler structure in those cases. I personally used it in an observable collection library, where I needed efficient indexed insert and the ability to compute the index of a node.
bogomipz 10y ago
Hi, I looked at some of your lecture videos which also look great. You have a wonderful teaching style. Is there any possibility of these lecture videos getting on youtube? Watching is a little choppy. Cheers.
nojvek 10y ago
This is awesome. I'm loving the model of computation Notes

0xmohit 10y ago

Thanks. Easy to remember domain :)

Jun8 10y ago

Looks great, thanks a lot! While causally browsing I noted the following in the 8-queens backtracking example: "The following recursive algorithm, essentially due to Gauss (who called it “methodical groping”), ..." Hilarious, especially given the current situation. I'd like to know what his original German term was.

ludwigschubert 10y ago
Oh this is a fun rabbit hole to go down: Gauss indeed wrote "methodisches tatonniren"[1], the latter of which is not a common German word, nor does it suggest grouping. I believe it to be an expression used at the time which was borrowed from French "tâtonner", which means "fumble", to describe a step-by-step process, "approaching" a solution. The closest I get in modern German is "herantasten", which in turn does not have an elegant English translation; you will have to take its elements "heran" (onto) and "tasten" (touch/feel/grope) individually to judge how close it is to fumble. So, methodical groping is not as far off as you might have thought! [1] https://books.google.com/books?id=3jEDAAAAQAAJ&pg=RA1-PA106&lpg=RA1-PA106&dq=8+königinnen+gauss&source=bl&ots=BuaJSJydKs&sig=1Z78TngV_y6IyQ8QNRwSVmvohvY&hl=en&sa=X&ved=0ahUKEwim0v3zhZHQAhXolFQKHStQCFYQ6AEIIjAB#v=onepage&q&f=true https://books.google.com/books?id=3jEDAAAAQAAJ&pg=RA1-PA106&... This may be a typo—the regular verb form would be "tatonnieren"—then again a lot of German spelling has changed since the time of those letters.
- bonzini 10y ago
  The word "tâtonner" should be the same as Italian "procedere (proceed) a tastoni", since usually the circumflex accent in French correspond to an "s" in Italian. The meaning is "feel your way"---proceed carefully and at every step feel what is around you, as if you were walking on complete darkness.
  - scns 10y ago
    >proceed carefully and at every step feel what is around you, as if you were walking on complete darkness. this would be a fitting translation of the german word "herantasten", which has nothing to do with groping btw
    - bonzini 10y ago
      Yup, "groping around" is not at all the same as "groping"!!!

mrkgnao 10y ago

TIL there is a .wtf TLD.

0xmohit 10y ago
There's also a .study TLD. And algorithms.study is available!

misoukrane 10y ago

Thanks for making the resources free.

ambar123 10y ago
What resource bro...

graycat 10y ago

Thanks. Given a directed graph with on each arc a maximum flow and a cost per unit of flow, how to find the least cost flows for a given total flow? That is linear programming. The simplex algorithm takes on a special form, and a simplex basic solution corresponds to a spanning tree. A simplex pivot is adding an arc to the tree to yield a circuit, and getting the cost of sending a unit of flow around the circuit evaluates that new arc. Etc. W. Cunningham defined a strongly feasible basic solution which avoids cycling. IIRC, D. Bertsekas has a good (polynomial) algorithm for that problem. I didn't see such mentioned in your table of contents. On my 14" screen, your PDF files would be much easier to read if the maximum number of characters per line was about 50.

deleted 10y ago

[deleted]

skiplist1 10y ago

I just skimmed over skiplist in point 10 of your book. The concept and definition of skiplist is easy to grok and it is well explained but in point 10 there is not any information as to when should I use a skiplist, what kind of problem a skiplist is a good tool to use. I have bookmarked your page, it seems to be a useful resource if it is complemented with a comparison and use case for all these data structures.

sobani 10y ago
A skiplist is a good candidate for problems where you are considering some kind of self-balancing tree. I find a skiplist to be the simpler structure in those cases. I personally used it in an observable collection library, where I needed efficient indexed insert and the ability to compute the index of a node.

bogomipz 10y ago

Hi, I looked at some of your lecture videos which also look great. You have a wonderful teaching style. Is there any possibility of these lecture videos getting on youtube? Watching is a little choppy. Cheers.

nojvek 10y ago

This is awesome. I'm loving the model of computation Notes