int is_magic_square(Matrix *A){
//Case that rows and columns not the same
//Not a Square grid, so cannot be square
if (A->rows != A->cols){
printf("Not a square matrix\n");
return 0;
}
//Getting sum of rows
double *allRowSum = row_sum(A);
//Get sum of columns
double *allColSum = col_sum(A);
//Get sum of diagnols
double *allDiag = diag_sum(A);
//Get total of first row - all others should be the same either way
double magic = allRowSum[0];
if (test_rows(allRowSum, A->rows, magic)){
if (test_cols(allColSum, A->cols, magic)){
if (test_diag(allDiag, magic)){
//If rows, cols, and diags are the same
//We have a magic square!
return 1;
}
}
}
return 0;
}
/*
http://en.wikipedia.org/wiki/Magic_square
A magic square is an arrangement of numbers (usually integers) in a
square grid, where the numbers in each row, and in each column, and
the numbers in the forward and backward main diagonals, all add up
to the same number.
Write a function called is_magic_square() that takes a matrix and
returns an int, 1 if the matrix is a magic square, and 0 otherwise.
Feel free to use row_sum().
*/
int is_magic_square(Matrix *M) {
// adding rows should be fastest due to caching, check that first
double *row_sums = row_sum(M);
double magnum = row_sums[0];
if (!is_uniform_vector(row_sums,M->rows,magnum)) {
return 0;
}
free(row_sums); // tidy tidy
// adding columns is slower, since it's more likely for the data to be
// spatially distant
double *col_sums = col_sum(M);
if (!is_uniform_vector(col_sums,M->cols,magnum)) {
return 0;
}
free(col_sums);
double *diag_sums = diag_sum(M);
return (diag_sums[0] == magnum) && (diag_sums[1] == magnum);
}
