Add challenge 79: Connected Components (Medium)

[claude]

Summary

• Adds challenge 79: Connected Components (Medium difficulty)
• Given an undirected graph with N vertices and M edges, label each vertex with the minimum vertex ID in its connected component
• Teaches: parallel label propagation with atomicMin, iterative convergence detection, work distribution across edges, and graph algorithm parallelization on GPU
• Not an element-wise operation — requires thinking about algorithm design, atomic operations, and convergence

Test plan

• All 6 starter files present (.cu, .pytorch.py, .triton.py, .jax.py, .cute.py, .mojo)
• challenge.html has all 4 sections: problem description, implementation requirements, example, constraints
• First example matches generate_example_test() values exactly
• generate_functional_test() covers 10 cases: self-loop, two-vertex graph, isolated vertices, disjoint pairs, line graph, star graph, grid graph, multi-component chains, random sparse graph, complete K4
• Performance test: N=1,000,000, M=5,000,000 (fits 5x in 16GB VRAM, ~220MB total)
• pre-commit run --all-files passes
• Validated with run_challenge.py --action submit: all tests pass on NVIDIA TESLA T4

🤖 Generated with Claude Code