Problem 722. Make a run-length companion vector
Given a vector x, return a vector r that indicates the run length of any value in x. Each element in r shows how many times the corresponding element in x has appeared consecutively.
Example:
Input x = [5 3 3 1 0 9 9 4 4 4 4 5 1 2 2] Output r = [1 1 2 1 1 1 2 1 2 3 4 1 1 1 2]
Solution Stats
Problem Comments
-
6 Comments
The first test case seems to be invalid answer. Please check it
Hi Wenwu: Could you be more specific about what you think the problem is?
See FileExchange's seqle . (disclaimer: I'm the author)
False exemple description
y=[];
for i = 1:length(delta)
test = max(delta(1:i));
maxsofar=max(delta(1:i-1));
test2=min(delta(1:i));
minsofar=min(delta(1:i-1));
if test == delta(i) && delta(i)~= maxsofar
y=[y,1];
elseif test2 == delta(i) && delta(i)~= minsofar
y=[y,-1];
else
y=[y,0];
end
end
this code despite its giving correct results it is rejected by the tests...
There are reasonable situations that are not addressed by the problem definition or tested for.
IE if there was a case such as x = [5 3 3 1 3 3 3] is the expected answer
r = [1 1 2 1 1 2 3] or
r = [1 1 2 1 2 2 3]?
Solution Comments
Show commentsProblem Recent Solvers638
Suggested Problems
-
The Goldbach Conjecture, Part 2
2332 Solvers
-
Get the area codes from a list of phone numbers
1053 Solvers
-
462 Solvers
-
471 Solvers
-
Find the Oldest Person in a Room
17484 Solvers
More from this Author50
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!