Your browser (Unknown 0) is no longer supported. Some parts of the website may not work correctly. Please update your browser.
Compute the total length covered by 1-dimensional segments.

You are given a table segments with the following structure:

create table segments ( l integer not null, r integer not null, check(l <= r), unique(l,r) );

Each record in this table represents a contiguous segment of a line, from l to r inclusive. Its length equals rl.

Consider the parts of a line covered by the segments. Write an SQL query that returns the total length of all the parts of the line covered by the segments specified in the table segments. Please note that any parts of the line that are covered by several overlapping segments should be counted only once.

For example, given:

l | r --+-- 1 | 5 2 | 3 4 | 6

your query should return 5, as the segments cover the part of the line from 1 to 6.

Copyright 2009–2024 by Codility Limited. All Rights Reserved. Unauthorized copying, publication or disclosure prohibited.