Codility - NumberOfDiscIntersections (JavaScript) Part 2/2: Optimized
Lesson 6 - Sorting
Psrt 2/2
Was a head scratching optimization. But once you got it, you got it. :)
Task Description:
We draw N discs on a plane. The discs are numbered from 0 to N − 1. An array A of N non-negative integers, specifying the radiuses of the discs, is given. The J-th disc is drawn with its center at (J, 0) and radius A[J].
We say that the J-th disc and K-th disc intersect if J ≠ K and the J-th and K-th discs have at least one common point (assuming that the discs contain their borders).
The figure below shows discs drawn for N = 6 and A as follows:
A[0] = 1
A[1] = 5
A[2] = 2
A[3] = 1
A[4] = 4
A[5] = 0
There are eleven (unordered) pairs of discs that intersect, namely:
discs 1 and 4 intersect, and both intersect with all the other discs;
disc 2 also intersects with discs 0 and 3.
Write a function:
function solution(A);
that, given an array A describing N discs as explained above, returns the number of (unordered) pairs of intersecting discs. The function should return −1 if the number of intersecting pairs exceeds 10,000,000.
Given array A shown above, the function should return 11, as explained above.
Write an efficient algorithm for the following assumptions:
N is an integer within the range [0..100,000];
each element of array A is an integer within the range [0..2,147,483,647].
On this page of the site you can watch the video online Codility - NumberOfDiscIntersections (JavaScript) Part 2/2: Optimized with a duration of hours minute second in good quality, which was uploaded by the user FRESH CODE SODA 01 June 2022, share the link with friends and acquaintances, this video has already been watched 195 times on youtube and it was liked by 1 viewers. Enjoy your viewing!
