In an array, arr = [a0, a1, …, aN-1] , the elements at indices i and j (where i < j) form an inversion if aI > aJ. In other words, inverted elements and are considered to be “out of order”. To correct an inversion, we can swap adjacent elements.
Wikipedia article about merge sort algorithm.
Source code examples on Github
Source code examples on Github
Wikipedia article about merge sort algorithm.
Combinatoric selections
There are exactly ten ways of selecting three from five, 12345:
123, 124, 125, 134, 135, 145, 234, 235, 245, and 345
In combinatorics, we use the notation, C(3,5) = 10.
Permuted multiples
It can be seen that the number, 125874, and its double, 251748, contain exactly the same digits, but in a different order.
Find the smallest positive integer, x, such that 2x, 3x, 4x, 5x, and 6x, contain the same digits.
Prime digit replacements
By replacing the 1st digit of the 2-digit number *3, it turns out that six of the nine possible values: 13, 23, 43, 53, 73, and 83, are all prime.
By replacing the 3rd and 4th digits of 56**3 with the same digit, this 5-digit...
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