Question

/**
* A collection of methods related to multi-dimensional arrays.
*/
public class Array2Lab {

/**
* Return whether k is in list.
* Precondition: the elements of list are not null.
* @param list the array to be searched.
* @param k the number to search for.
* @return true if k is an element of list, and false otherwise.
*/
public static boolean contains(Object[][] list, Object k) {
return false;
}
  
/**
* Create a String that has the contents of list. Each row of list should be on a separate line,
* separated by spaces, and surrounded by { and }.
* The first line of of the output should start with an additional {, each other line of the output
* should start with a space, and the last line of the output should have an additional {.
* For example: {{1, 2}, {3, 4}} should be formatted in the String as:
* {{1 2}
* {3 4}}
* @param list the array to print.
* @return the elements of the array, separated by spaces, and surrounded by { and }, with each row on a separate line.
*/
public static String arrayToString(int[][] list) {
return null;
}

/**
* Create a new array that "flips" a rectangular region of matrix about the diagonal. So, each row of the output should be a column of the input.
* Precondition: The region of matrix[rowStart...rowEnd][colStart...colEnd] exists.
* @param matrix the input two dimensional array.
* @param rowStart the index of the first row of the rectangular region to flip.
* @param rowEnd the index of the last row of the rectangular region to flip.
* @param colStart the index of the first column of the rectangular region to flip.
* @param colEnd the index of the last column of the rectangular region to flip.
*/
public static int[][] transpose(int[][] matrix, int rowStart, int rowEnd, int colStart, int colEnd) {
return null;
}

/**
* Creates a new array that is a copy of the input matrix, except that one row and one column have been removed.
* Precondition: the row index is between 0 (inclusive) and the number of rows of matrix (not inclusive)
* @param matrix the input two dimensional array
* @param row the index of the row to remove
* @param col the index of the column to remove
*/
public static int[][] removeRowAndCol(int[][] matrix, int row, int col) {
return null;
}
}

Answer 1

ANSWER...

OUTPUT SCREEN SHOT:-

COPY CODE:-

//Below is your code: -

/**
* A collection of methods related to multi-dimensional arrays.
*/
public class Array2Lab {

/**
* Return whether k is in list. Precondition: the elements of list are not null.
*
* @param list the array to be searched.
* @param k the number to search for.
* @return true if k is an element of list, and false otherwise.
*/
public static boolean contains(Object[][] list, Object k) {
for (int i = 0; i < list.length; i++) {
for (int j = 0; j < list[i].length; j++) {
if (list[i][j].equals(k)) {
return true;
}
}
}
return false;
}

/**
* Create a String that has the contents of list. Each row of list should be on
* a separate line, separated by spaces, and surrounded by { and }. The first
* line of of the output should start with an additional {, each other line of
* the output should start with a space, and the last line of the output should
* have an additional {. For example: {{1, 2}, {3, 4}} should be formatted in
* the String as: {{1 2} {3 4}}
*
* @param list the array to print.
* @return the elements of the array, separated by spaces, and surrounded by {
* and }, with each row on a separate line.
*/
public static String arrayToString(int[][] list) {
String output = "{\n";
for (int i = 0; i < list.length; i++) {
output += " {";// added space as per question
for (int j = 0; j < list[i].length; j++) {
output = output + list[i][j] + " ";
}
output = output.substring(0, output.length() - 1);
output += "}\n";
}
output += "}";
return output;
}

/**
* Create a new array that "flips" a rectangular region of matrix about the
* diagonal. So, each row of the output should be a column of the input.
* Precondition: The region of matrix[rowStart...rowEnd][colStart...colEnd]
* exists.
*
* @param matrix the input two dimensional array.
* @param rowStart the index of the first row of the rectangular region to flip.
* @param rowEnd the index of the last row of the rectangular region to flip.
* @param colStart the index of the first column of the rectangular region to
* flip.
* @param colEnd the index of the last column of the rectangular region to
* flip.
*/
public static int[][] transpose(int[][] matrix, int rowStart, int rowEnd, int colStart, int colEnd) {
int transpose[][] = new int[matrix.length][];
for (int i = 0; i < matrix.length; i++) {
transpose[i] = new int[matrix[i].length];
for (int j = 0; j < matrix[i].length; j++) {
transpose[i][j] = matrix[i][j];
}
}
for (int c = rowStart; c < rowEnd - 1; c++) {
for (int d = colStart; d < colEnd - 1; d++) {
transpose[d][c] = matrix[c][d];
}
}

return transpose;
}

/**
* Creates a new array that is a copy of the input matrix, except that one row
* and one column have been removed. Precondition: the row index is between 0
* (inclusive) and the number of rows of matrix (not inclusive)
*
* @param matrix the input two dimensional array
* @param row the index of the row to remove
* @param col the index of the column to remove
*/
public static int[][] removeRowAndCol(int[][] matrix, int row, int col) {
int[][] newArr = new int[matrix.length - 1][];
int newArrRow = 0;
for (int i = 0; i < matrix.length; ++i) {
if (i == row)
continue;
newArr[newArrRow] = new int[matrix[i].length - 1];
int newArrCol = 0;
for (int j = 0; j < matrix[i].length; ++j) {
if (j == col)
continue;

newArr[newArrRow][newArrCol] = matrix[i][j];
++newArrCol;
}
++newArrRow;
}
return newArr;
}

public static void main(String[] args) {
Integer[][] arr = { { 1, 2, 3, 4, 5 }, { 6, 7, 8, 9, 10 }, { 11, 12, 13, 14, 15 }, { 16, 17, 18, 19, 20 } };
int[][] arr1 = { { 1, 2, 3, 4, 5 }, { 6, 7, 8, 9, 10 }, { 11, 12, 13, 14, 15 }, { 16, 17, 18, 19, 20 } };
System.out.println("Is 17 present in array: " + contains(arr, 17));
System.out.println("Is 21 present in array: " + contains(arr, 21));
System.out.println("Arrays to String representation: ");
System.out.println(arrayToString(arr1));
int[][] transposedArray = transpose(arr1, 1, 5, 1, 5);
System.out.println("Arrays to String representation after transpose: ");
System.out.println(arrayToString(transposedArray));

int[][] removedRowAndColArr = removeRowAndCol(arr1, 2, 3);
System.out.println("Arrays to String representation after removing row 2 and col 4: ");
System.out.println(arrayToString(removedRowAndColArr));
}
}

Output

Is 17 present in array: true
Is 21 present in array: false
Arrays to String representation:
{
{1 2 3 4 5}
{6 7 8 9 10}
{11 12 13 14 15}
{16 17 18 19 20}
}
Arrays to String representation after transpose:
{
{1 2 3 4 5}
{6 7 12 17 10}
{11 8 13 18 15}
{16 9 14 19 20}
}
Arrays to String representation after removing row 2 and col 4:
{
{1 2 3 5}
{6 7 8 10}
{16 17 18 20}
}