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Zonal Informatics Olympiad
IARCS Stage-1 informatics olympiad. Pen-and-paper paper on algorithmic problem-solving — no programming language knowledge required. 4 problems in 3 hours.
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Source: official exam authority notification · refreshed weekly. How this works →
Free ZIO preparation on Shishya
Take expert-curated mocks, practise previous year papers, and Ask Shishya when you're stuck — verified by students who cleared the same path. All free, no credit card. Sign in with Google to begin.
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10 questions across the syllabus to see where you stand.
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ZIO — Quick Practice
FULL20 questions · 180 min
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What can I get from ZIO?
Mock-score → expected rank → likely outcome. Use the mocks below to find your current band, then plan how many marks you need to climb.
IOI track — Elite tier
92–100% · Post-based exam (no numeric rank)
National-level excellence
82–92% · Post-based exam (no numeric rank)
Top zonal performers
70–82% · Post-based exam (no numeric rank)
INOI qualification likely
55–70% · Post-based exam (no numeric rank)
Borderline qualification zone
35–55% · Post-based exam (no numeric rank)
Below qualifying threshold
0–35% · Post-based exam (no numeric rank)
AI-curated from historic cut-off patterns. Always verify with the latest official notification before making decisions.
Students who cleared ZIO 2026 can now register for the Indian National Olympiad in Informatics (INOI). The registration deadline is in the coming weeks, and participants must complete enrollment to be eligible for the national-level competition.
Source →The Indian Association for Research in Computing Science (IARCS) has announced ZIO 2026 results. Qualified students can now check their scores and eligibility for INOI on the official portal. Successful candidates will receive detailed instructions for the next round.
Source →IARCS has published preliminary information for ZIO 2027, including recommended topics in algorithms, data structures, and problem-solving. Students preparing for the next cycle should focus on computational thinking and programming fundamentals.
Source →The official IARCS website now features updated practice problems and past ZIO question papers. These resources are designed to help students strengthen their algorithmic problem-solving skills for upcoming Olympiad competitions.
Source →ZIO 2027 registration opens
149 days awayFri, 23 Oct, 2026
Online registration portal opens for next year's Zonal Informatics Olympiad
ZIO 2027 registration deadline
204 days awayThu, 17 Dec, 2026
Last date to complete registration for ZIO 2027
📌ZIO 2027 exam date
229 days awayMon, 11 Jan, 2027
Zonal Informatics Olympiad examination conducted at designated centers
ZIO 2027 results announcement
259 days awayWed, 10 Feb, 2027
Results published on IARCS website with list of qualifiers for INOI
INOI 2027 registration for ZIO qualifiers
264 days awayMon, 15 Feb, 2027
Registration window opens for qualified students to enroll in INOI
📌INOI 2027 exam date
294 days awayWed, 17 Mar, 2027
Indian National Olympiad in Informatics conducted for ZIO qualifiers
Click any topic to read study notes
Introduction to Algorithms
What an algorithm is, step-wise problem decomposition, pseudocode reading.
Measuring Algorithm Efficiency
Time and space complexity intuition, big-picture growth rates without formal Big-O.
Searching
Linear search, binary search and variants over sorted/unsorted data.
Sorting
Selection, insertion, merge and quick sort intuition; stability and order properties.
Recursion
Recursive thinking, base/recursive cases, recursion tree, divide-and-conquer.
Dynamic Programming Intuition
Overlapping subproblems, memoisation, tabulation on small input sizes.
Greedy Algorithms
Local optimal choices, interval scheduling, coin-change-style ad-hoc greedy.
Basic Graph Concepts
Vertices, edges, directed/undirected graphs, paths, cycles, connectivity.
Graph Traversal
Breadth-first and depth-first traversal as conceptual exploration strategies.
Shortest Paths
Shortest-path intuition on grids and small graphs without formal algorithms.
Trees
Rooted trees, binary trees, parent/child traversal, tree counting puzzles.
Basic Data Structures
Arrays, lists, stacks, queues — used as tools for problem modelling.
Simulation
Mentally or on paper simulating a process or rule on small concrete inputs.
Invariants and Monovariants
Quantities preserved or strictly changing across steps — proving outcomes.
Case Analysis
Splitting a problem into exhaustive cases and resolving each.
Counting Principles
Sum and product rules, permutations, combinations applied to small enumerations.
Pigeonhole Principle
Existence arguments via pigeons/holes — colourings, residues, pairs.
Parity and Modular Reasoning
Even/odd reasoning, basic modular arithmetic for invariants.
Elementary Number Theory
Divisibility, gcd/lcm reasoning, prime factorisation puzzles.
Combinatorial Games
Winning/losing positions, Nim-like games, strategy stealing.
Constructive Problems
Building an explicit example/configuration that satisfies given rules.
Optimisation Puzzles
Finding minimum/maximum of a quantity under given constraints.
Scheduling and Ordering
Sequencing tasks, jobs or moves to satisfy precedence/deadline rules.
Grid and Geometry Puzzles
Reasoning on 2D grids — paths, colourings, tilings, distance puzzles.
Three Concrete Inputs Format
ZIO-style problems — solve three increasingly large concrete inputs by spotting an efficient method.
IOITC selection camp (tentative period begins)
324 days awayFri, 16 Apr, 2027
Training camp for International Olympiad in Informatics team selection
Sets and Logic
Inclusion-exclusion, propositional logic, truth tables in puzzles.