Name: ________________________________

Honor Code Acknowledgment: _____________________________

CPS 6, Summer 1999                 Random Quiz 9

Due: Friday, June 18, 1999                 7 points

Problem 1: Summing up the Kth (3 pts)

Write the function KthColumnSum whose header is given below. The function returns the sum of the values in column k of two-dimensional array mat. 
    int KthColumnSum(const Matrix<int> & mat, int k, int numRows)
    // precondition: 0 <= k < mat.Cols()
    //               numRows = # of rows in the matrix mat
    // postcondition: returns sum of all values in column k of mat
    {

Problem 2: Transpose (4 points)

A matrix is transposed if the rows become columns and the columns become rows, e.g., the matrix is rotated 90 degrees. The matrix on the left below is transposed into the matrix on the right. 
    1  2  3  4          1  5  9
    5  6  7  8          2  6 10
    9 10 11 12          3  7 11
                        4  8 12
Write the function Transpose whose header is shown below. You'll need to use Matrix member functions Rows(), Cols(), and SetSize(int rows, int cols). The first two return the number of rows and columns in a matrix, and SetSize is used to set the number of rows and columns. 
  void Transpose(const Matrix<double> & a, Matrix<double> & b)
  // precondition: a has a.Rows() rows and a.Cols() columns.
  // postcondition: b is the transpose of a