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How can I put strings in an array, split by new line?
...h line breaks in my database. I want to convert that string into an array, and for every new line, jump one index place in the array.
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Can hash tables really be O(1)?
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You have two variables here, m and n, where m is the length of the input and n is the number of items in the hash.
The O(1) lookup performance claim makes at least two assumptions:
Your objects can be equality compared in O(1) time.
There will be few ha...
Is Big O(logn) log base e?
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Kinopkio and bcat, thanks for helping it become useful. It was not very well-written at first. :)
– Heath Hunnicutt
Oct 15 '09 at 1:04
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How do I use arrays in C++?
...sed virtually everywhere. C++ provides abstractions that are easier to use and less error-prone ( std::vector<T> since C++98 and std::array<T, n> since C++11 ), so the need for arrays does not arise quite as often as it does in C. However, when you read legacy code or interact with a...
Algorithm to calculate the number of divisors of a given number
...st of primes you'll need to see how many of those primes act as a divisor (and how often).
Here's some python for the algo Look here and search for "Subject: math - need divisors algorithm". Just count the number of items in the list instead of returning them however.
Here's a Dr. Math that explai...
Best way to split string into lines
...ible solutions I prefer the one using regular expressions since only that handles all source platforms correctly.
– Konrad Rudolph
Jan 20 '11 at 17:14
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How can I replace a newline (\n) using sed?
...w can I replace a newline (" \n ") with a space (" ") using the sed command?
42 Answers
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Throwing cats out of windows
...y write a little DP (dynamic programming) for the general case of n floors and m cats.
The main formula, a[n][m] = min(max(a[k - 1][m - 1], a[n - k][m]) + 1) : for each k in 1..n, should be self-explanatory:
If first cat is thrown from k-th floor and dies, we now have k - 1 floors to check (all...
Code Golf - π day
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In dc: 88 and 93 93 94 96 102 105 129 138 141 chars
Just in case, I am using OpenBSD and some supposedly non-portable extensions at this point.
93 chars. This is based on same formula as FORTRAN solution (slightly different results t...
How to append rows to an R data frame
...rs of the type you want for each column, insert values into those vectors, and then, at the end, create your data.frame.
Continuing with Julian's f3 (a preallocated data.frame) as the fastest option so far, defined as:
# pre-allocate space
f3 <- function(n){
df <- data.frame(x = numeric(n)...