GATE · Algorithms · United Kingdom

Algorithms for the GATE Exam — UK candidates

10% of the GATE test plan. Sorting, searching, dynamic programming, greedy methods, graph algorithms, and asymptotic complexity — approximately 10% of GATE CS. Calibrated for British candidates.

Most exam coaching covers the curriculum at the same depth across all topics. That misses the asymmetry of high-stakes testing: a few topics carry disproportionate weight on the score. Algorithms sits at roughly 10% of the Graduate Aptitude Test in Engineering content distribution — Algorithms is the most analytical topic in GATE CS. Questions test recurrence-relation solving, DP state formulation, and correctness proofs for greedy algorithms. Dynamic programming is the single highest-difficulty sub-topic; GATE Advanced questions on DP require both design and complexity analysis. Pass rates for the GATE are published annually by the awarding body and vary by cohort and locale. For UK candidates preparing for GATE, the calibration of study to local context matters: UK candidates often take exams for both domestic licensure (NMC, GMC) and migration purposes. IELTS UKVI is a separate, higher-stakes track.

Pass rates for GATE (United Kingdom) are published periodically by the awarding body.

Common failure modes

These are the patterns that cause most candidates to lose marks on this topic. Recognising them in advance is half the work.

!Solving recurrences incorrectly using the Master Theorem — misidentifying which case applies
!Confusing time complexity of graph algorithms (Dijkstra with a binary heap is O((V+E) log V), not O(V²))
!Proposing greedy solutions without proving the greedy-choice and optimal-substructure properties
!Using overlapping-subproblem intuition but defining the wrong DP state (leading to exponential states)
!Forgetting that Bellman-Ford handles negative edges but not negative cycles; Dijkstra fails on negative edges

Study tips

1Memorise the Master Theorem: T(n) = aT(n/b) + f(n). Know all three cases and their conditions, including the 'regularity condition' for Case 3.
2Drill classic DP problems: 0/1 knapsack, longest common subsequence, matrix chain multiplication, and coin change. GATE recycles these patterns in new settings.
3For sorting, know the lower bound Ω(n log n) for comparison-based sorting, and the O(n) cases: counting sort, radix sort, bucket sort.
4Trace Dijkstra and Bellman-Ford step-by-step on a small graph (5 nodes) until you can do it without notes.
5Practice asymptotic notation questions: ranking functions by growth rate is a reliable 1-mark source.
6In the UK, GATE schedules and reschedules align with state holiday calendars and post-Brexit fee adjustments — confirm pricing on the awarding body's site before booking.

Sample GATE Algorithms questions

These sample items mirror the format and difficulty of real GATE questions. Practice with thousands more on the free Koydo question bank.

1
Which of the following algorithms does NOT work correctly on graphs with negative-weight edges?
- ABellman-Ford
- BFloyd-Warshall
- CDijkstra's algorithmCorrect
- DDFS-based topological sort with relaxation
Why this answer?
(GATE CS style) Dijkstra's algorithm uses a greedy approach that assumes once a vertex is settled its distance is final. A negative-weight edge can later provide a shorter path, violating this assumption. Bellman-Ford and Floyd-Warshall handle negative edges (but not negative cycles).
2
The recurrence T(n) = 2T(n/2) + n has solution:
- AO(n)
- BO(n log n)Correct
- CO(n²)
- DO(log n)
Why this answer?
(GATE CS style) By the Master Theorem: a = 2, b = 2, f(n) = n. n^(log_b a) = n^1 = n. Since f(n) = Θ(n^(log_b a)), this is Case 2, giving T(n) = Θ(n log n).
3
The best-case time complexity of QuickSort is:
- AO(n²)
- BO(n log n)Correct
- CO(n)
- DO(log n)
Why this answer?
(GATE CS style) In the best case, each partition splits the array into two equal halves, giving the recurrence T(n) = 2T(n/2) + O(n), which solves to O(n log n). Worst-case (always picking min/max as pivot) is O(n²).

Frequently asked questions

Is dynamic programming the hardest algorithms topic in GATE?

DP questions are consistently rated the highest difficulty in GATE CS. However, GATE DP questions follow a small set of canonical patterns — knapsack, LCS, matrix chain, edit distance — so targeted practice pays off more than studying DP theory abstractly.

How many algorithms questions appear in GATE CS?

GATE 2024 allocated approximately 8–10 marks to Algorithms (a mix of 1-mark and 2-mark questions). Questions often require choosing the correct complexity class or tracing an algorithm on a small example, rather than writing code.

What is the GATE pass rate for British candidates?

Pass rates for GATE candidates in United Kingdom are published periodically by the awarding body. Practice questions, full-length simulations, and weak-area drills are the highest-impact way to improve your odds.

How long should British candidates study Algorithms for the GATE?

For most candidates, focused mastery of Algorithms requires 20–40 hours of deliberate practice — drilling sample questions, reviewing failure modes, and timing yourself against exam conditions. UK candidates often take exams for both domestic licensure (NMC, GMC) and migration purposes. IELTS UKVI is a separate, higher-stakes track. Combine Algorithms study with full-length mock exams in the final two weeks before your test date.

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Related study guides

Regulatory citation: GATE 2024 CS Syllabus — Algorithms (Sorting, Searching, Asymptotic Complexity, Graph Algorithms, Dynamic Programming, Greedy).