P-7.4 Timed Practice: Arrays, Strings and Hashing
You can work a screening-level array, string or counting question inside its time limit, and your error log tells you which mistake you keep making.
The largest question area in a first round, and the one where speed is built rather than learned. The structures are taught in the data structures module; this is the same material under a clock, at the depth a screening round sets, which stops well short of the competitive-programming versions of the same problems. Work it in the language you named as your first skill: the courses attached here teach the structures in Python and in Java rather than in notation, and Funcognito writes no questions of its own, so every set named here is somebody else's and is named as such.
Work through these
Set a timer for twenty minutes and work three array questions from start to tested answer
Three in twenty is roughly the pace a screening test sets. The first attempt is meant to feel impossible, and the point is to find out where the time actually went.
NPTEL: Programming, Data Structures and Algorithms using Python · CourseStrings as arrays: reversing, counting characters, and comparing without a second copy
String questions are array questions with a different name, and the extra difficulty is usually memory rather than logic. Doing them in place is what an interviewer follows up on.
Write one counting question twice: once by scanning, once with a hash table, and time both
Writing the slow version first is not wasted work; it is the version you fall back on when the clock runs out. Timing both makes the improvement a measurement rather than a belief.
Take a timed data structures set, and mark the areas you were slow on rather than the ones you got wrong
Speed and accuracy fail differently and need different practice. Slow-but-right areas are the ones that cost the most marks under a real clock.
IndiaBIX: Online Data Structures Test · TutorialKeep an error log: the question, the mistake, and the fix, one line each
Most errors repeat, and a log shows which three reasons account for most of yours. It is the same page that works for the aptitude paper, applied to code.
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