Equivalence of L0 and L1 Minimizations in Sudoku Problem
  Sudoku puzzles can be formulated and solved as a sparse linear system of equations. This problem is a very useful example for the Compressive Sensing (CS) theoretical study. In this study, the equivalence of Sudoku puzzles L0 and L1 minimizations is analyzed. In particular, 17-clue (smallest number of clues) uniquely completable puzzles with sparse optimization algorithms are studied and divided into two types, namely, type-I and -II puzzles. The solution of L1 minimization for the type-I puzzles is unique, and the sparse optimization algorithms can solve all of them exactly. By contrast, the solution of L1 minimization is not unique for the type-II puzzles, and the results of algorithms are incorrect for all these puzzles. Each empty cell for all type-II puzzles is examined. Results show that some cells can change the equivalence of L0 and L1 minimizations. These results may be helpful for the study of equivalence of L0 and L1 norm minimization in CS. 
Linyuan Wang, Wenkun Zhang, Bin Yan, Ailong Cai
math.OC