Competitive Programming Tools

Free competitive programming tools — graph visualizer, segment tree builder, bit visualizer, bitmask planner, Big-O complexity calculator, interval merger, and more.

17 tools
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Code Formatter

Format and beautify C++, Java, and Python code with consistent indentation. 100% client-side — no code leaves your browser.

Matrix Generator

Generate grid/matrix inputs for competitive programming. Random, zeros, identity, or sequential fill. Outputs in multiple formats.

Complexity Calc

Estimate Big-O operations and runtime for any N. Interactive reference table for all complexity classes from O(1) to O(N!).

Bit Visualizer

Toggle 32/64-bit grids. Click bits to flip them live and see decimal recalculate. Shows popcountll, clzll, ctzll, and MSB instantly.

Bitmask Planner

Input set size N (≤12). Visualize all 2^N bitmasks, submask iterations, and generate ready-to-paste C++ DP skeleton.

Prime Factors

Input N to instantly view prime factorization, total divisors, Euler totient, and full sorted divisors list with prime highlighting.

MEX Calc

Input a comma-separated array and see the MEX (Minimum Excluded) computed step-by-step with frequency table and visual walkthrough.

Interval Merger

Input pairs of ranges like [1,4],[3,7]. Visualizes overlaps on a timeline and collapses them into merged segments instantly.

Matrix Rotation

Input a 2D matrix, choose 90°/180°/270° CW or CCW rotation. See the visual index shift and get the C++ implementation.

PBDS Generator

Generate ready-to-paste C++ Order Statistics Tree code. Configure key type, comparator, and duplicate support. One-click copy.

Segment Tree

Input an array, choose sum/min/max/gcd. See the segment tree visualization and get a complete C++ class template to copy.

Graph Visualizer

Paste CP-style edge lists and watch a force-directed graph build itself. Drag nodes, toggle directed/undirected, 0/1-indexed. Outputs adjacency list with one-click copy.

Stress Tester

Paste your brute force, optimal solution, and test generator. Instantly get a downloadable Python or Bash stress test script that finds counter-examples automatically.

Modulo Calc

Compute modular inverse, fast power modulo, and nCr mod p using BigInt precision. One-click C++ snippet output for each operation.

Binary Visualizer

Interactive 32-bit grid — click any bit to flip it live. Shows decimal, hex, binary, popcount, clz, ctz, MSB, and common bitwise operations instantly.

Convex Hull

Click the canvas to place coordinate points. Renders the enclosing convex hull polygon live using Andrew's monotone chain. Outputs C++ points vector.

Path Finder

Paint walls on an N×M grid, set start and end cells, then run BFS to visualize the shortest path. Copy the grid as a C++ 2D vector instantly.

Frequently Asked Questions

Everything you need to know about competitive programming tools

Who are these competitive programming tools for?
These tools are designed for competitive programmers of all levels — from beginners on Codeforces to experts preparing for ICPC or IOI.
Can I visualize my own test cases?
Yes. Tools like the Graph Visualizer, Grid Path Finder, and Binary Matrix Visualizer let you input custom data and see instant visual feedback.
Are these tools allowed during online contests?
These are learning and practice tools. Always check your contest platform's rules — most allow offline analysis and planning tools.