<summary>Linear programming and integer programming</summary> See the comments at the top of linear_solver.h for an introduction to linear programming and integer programming. - linear_solver.h: the point of entry for the wrapper that provides a simple and unified interface to several linear programming and mixed integer programming solvers. - linear_solver.cc: the C++ code of the linear solver wrapper that is common to all solvers accessible through the wrapper. - *_interface.cc: each file corresponds to one of the solver accessible through the wrapper. - *.swig: the SWIG code that makes the wrapper available in Java and Python. - linear_solver.proto: the protocol buffer for mathematical programming problems.