This two volume set LNCS 14422-14423 constitutes the refereed proceedings of the 29th International Conference, COCOON 2023, held in Hawaii, HI, USA, during December 2023. They are organized in the following topical sections:Part I : Combinatorics and Algorithms; and Algorithm in Networks.Part II: Complexity and Approximation;

Combinatorics and Algorithms.- Quantum Query Lower Bounds for Key Recovery Attacks on the Even-Mansour Cipher.- Extended formulations via decision diagrams.- Greedy Gray codes for Dyck words and ballot sequences.- Efficiently-Verifiable Strong Uniquely Solvable Puzzles and Matrix Multiplication.- (min,+) Matrix and Vector Products for Inputs Decomposable into Few Monotone Subsequences.- A Sub-quadratic Time Algorithm for Computing the Beacon Kernel of Simple Polygons.- An Approach to Agent Path Planning under Temporal Logic Constraints.- The Heterogeneous Rooted Tree Cover Problem.- The Hardness of Optimization Problems on the Weighted Massively Parallel Computation Model.- The Regularized Submodular Maximization via the Lyapunov Method.- Topological network-control games.- Lower Bounds of Functions on Finite Abelian Groups.- A Discharging Method: Improved Kernels for Edge Triangle Packing and Covering.- Random Shortening of Linear Codes and Applications.- Algorithms for Full-View Coverage of Targets with Group Set Cover.- Improved bounds for the binary paint shop problem.- Algorithmic Solution in Applications.- Fitch Graph Completion.- Deterministic Primal-Dual Algorithms for Online k-way Matching with Delays.- Diversity and freshness-aware regret minimizing set queries.- A Modified EXP3 in Adversarial Bandits with Multi-User Delayed Feedback.- Cabbage Can’t Always be Transformed into Turnip: Decision Algorithms for Sorting by Symmetric Reversals.- k-median/means with outliers revisited: a simple fpt approximation.- A cost-sharing scheme for the $k$-product facility location game with penalties.- Algorithm in Networks.- Maximizing Diversity and Persuasiveness of Opinion Articles in Social Networks.- Stochastic Model for Rumor Blocking Problem in Social Networks under Rumor Source Uncertainty.- Algorithms for Shortest Path Tour Problem in Large-Scale Road Network.- Solving systems of linear equations through zero forcing sets.- Profit Maximization for Competitive Influence Spread in Social Networks.- Improved Approximation Algorithms for Multidepot Capacitated Vehicle Routing.- On the Minimum Depth of Circuits with Linear Number of Wires Encoding Good Codes.- Approval-Based Participatory Budgeting with Donations.