tilir/concrete

Different computability and combinatorics experiments and visualizations

Concrete mathematics

Different computability and combinatorics experiments and visualizations. Pure fun.

Building and testing repo

Release build

cmake -G Ninja -B build -DCMAKE_CXX_COMPILER=g++-12 -DCMAKE_BUILD_TYPE=Release .
cmake --build build
env CTEST_OUTPUT_ON_FAILURE=1 cmake --build build --target test

Debug build

cmake -G Ninja -B debug -DCMAKE_CXX_COMPILER=g++-12 -DCMAKE_BUILD_TYPE=Debug .
cmake --build debug
env CTEST_OUTPUT_ON_FAILURE=1 cmake --build debug --target test

special configuration options

• Include apps with SDL2 visualization: -DVISUAL=1

Applications

Most of applications composes to each other nicely.

$ ./build/apps/randperm -seed=1
10
10 1 3 6 8 5 7 4 2 9

Then say we want to check if it is Baxter's

$ ./build/apps/randperm -seed=1 | ./build/apps/is-baxters
0

Some apps have batch mode. In batch mode size prepends series of entities:

Try:

$ echo 4 | ./build/apps/allperms | ./build/apps/is-baxters -batch -combine

Every app have option -help.

Below all apllications described briefly

Brace generators

• allbraces -- spills all properly braced expressions
• randbraces -- output random correctly braced expression

Permutation related

• allperms -- spills all permutations of 1..N
• invperm -- outputs reversed permutation
• is-baxters -- says if permutation is baxters or not
• permloops -- input permutation output loop format
• randperm -- output random permutation

Combinations related

• allsubsets -- spills all subsets of 0..(N-1) or with any labels

Trees related

• readbst -- application reads permutation or brace expression and outputs a tree
• readtwin -- application reads permutation and outputs twin tree or equivalent baxters