// AP Computer Science, A Exam, 1996, Question 4, part B in C++
// also AB Exam, question 2

void RemoveCross(apmatrix<int> & m, int R, int C)
// precondition: 0 <= R < m.numRows(); 0 <= C < m.numCols()
// postcondition: row with index R and column with index C
//                have been removed from m
{
    int j,k;
    int rows = m.numRows();         // store value, call only once
    int cols = m.numCols();         / per loop iteration

    // shift all columns to the left once,
    // starting with index c

    for(j=0; j < rows; j++)
    {
	for(k=C; k < cols-1; k++)     // avoid bad index at right
	{
	    m[j][k] = m[j][k+1];      // shift left
	}
    }

    // now shift rows "up", matrix is a vector of vectors

    for(j=R; j < rows-1; j++)        // avoid bad index at bottom
    {
	m[j] = m[j+1];               // shift up
    }

    m.resize(rows-1,cols-1);         // resize the matrix
}