Programming Practice Create a method: public static int[] productOfColumns(int[]
ID: 3718235 • Letter: P
Question
Programming Practice
Create a method: public static int[] productOfColumns(int[][] matrix)
Takes a rectangular matrix and produces an array containing the product of each column. The returned array must have length equal to the number of columns in the matrix and the ith entry must contain the product of the ith column. You may assume that if matrix is not null then it is nonempty and all rows are nonempty with the same length. Essentially if matrix is not null, then its no smaller (dimension wise) than {{1}}. If matrix is null, it should return null. E.g. If matrix = {{1, 2, 3}, {2, 2, 0}} this would return {2, 4, 0}; if matrix = {{1,2},{3,4},{5,6}}, this would return {15, 48}.
Parameters: matrix — A rectangular 2-d array of ints.
Returns: An array containing the product of each column.
Explanation / Answer
ProductOfMatrixCols.java
public class ProductOfMatrixCols {
public static void main(String[] args) {
//Declaring 2-D matrix
int matrix[][]= {{1, 2, 3}, {2, 2, 0}};
//calling the method by passing the 2-D array as argument
int matrixColProd[]=productOfColumns(matrix);
//Displaying the Resultant Matrix
System.out.println("Displaying the Result :");
for(int i=0;i<matrixColProd.length;i++)
{
System.out.print(matrixColProd[i]+" ");
}
System.out.println();
}
//This method will find the product of columns of 2-D matrix
private static int[] productOfColumns(int[][] matrix) {
int cols=matrix[0].length;
int res[]=null;
if(matrix==null)
{
return null;
}
else
{
res=new int[cols];
int prod;
for(int i=0;i<matrix[0].length;i++)
{
prod=1;
for(int j=0;j<matrix.length;j++)
{
prod*=matrix[j][i];
}
res[i]=prod;
}
}
return res;
}
}
_____________________
Output:
Displaying the Result :
2 4 0
______________
ProductOfMatrixCols.java
public class ProductOfMatrixCols {
public static void main(String[] args) {
//Declaring 2-D matrix
int matrix[][]={{1,2},{3,4},{5,6}};
//calling the method by passing the 2-D array as argument
int matrixColProd[]=productOfColumns(matrix);
//Displaying the Resultant Matrix
System.out.println("Displaying the Result :");
for(int i=0;i<matrixColProd.length;i++)
{
System.out.print(matrixColProd[i]+" ");
}
System.out.println();
}
//This method will find the product of columns of 2-D matrix
private static int[] productOfColumns(int[][] matrix) {
int cols=matrix[0].length;
int res[]=null;
if(matrix==null)
{
return null;
}
else
{
res=new int[cols];
int prod;
for(int i=0;i<matrix[0].length;i++)
{
prod=1;
for(int j=0;j<matrix.length;j++)
{
prod*=matrix[j][i];
}
res[i]=prod;
}
}
return res;
}
}
____________________
Output:
Displaying the Result :
15 48
______________Thank You
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.