public SolveResult DoBacktrackingProof(SudokuGrid grid, TextWriter log) { //verbose = false; solnsFound = 0; int osc = tsc; BacktrackingProof(log); if (solnsFound == 0) { return(SolveResult.NoSolutions); } if (solnsFound == 1) { for (int i = osc; i < sampleSoln.Length; ++i) { grid.SelectCandidate(sampleSoln[i]); } return(SolveResult.SingleSolution); } return(SolveResult.MultipleSolutions); }