- made a template and moved vectorHaveOnlyZeros's definition to header;
- removed function isNotZero();
fixed function haveZeroRows(): not it returns boolean values
added function haveZeroColumns()
refactored code
added constants DETERMINANT_OF_MATRIX_0X0 and DETERMINANT_OF_MATRIX_WITH_ZERO_ROWS_OR_COLUMNS
added returning of constant
DETERMINANT_OF_MATRIX_WITH_ZERO_ROWS_OR_COLUMNS's
value at function calculateDeterminantViaTriangularMatrix()
if matrix has zero rows or columns
added returning of constant DETERMINANT_OF_MATRIX_0X0's value
at function calculateDeterminantViaTriangularMatrix() when the matrix'
size 0x0
changed names for test where vector of int is tested
added case DoubleVectorWithOnlyZeros to test VectorHaveOnlyZeros
added tests for haveZeroRows() and haveZeroColumns()