Question

In Java, declare a 2-dim array called matrix which holds up to 35 values (of type int) 5 rows and 7 columns each.

Using sub-array processing and modularity, create methods to do the following:

1. Fill the array matrix with random numbers between 1-100

2. Compute the cumulative sum of the array matrix

3. Using column-wise processing compute, and print the cumulative sum of all the elements in each column

4. Compute the min value of the array matrix

5. Using column-wise processing, compute and print the minimum value in each column

6. Create and copy the transpose of the array matrix into a new 2-dim array m_transpose

Generate output similar to the sample output below:

Initial Output:

0 0 0 0 0 0 0

0 0 0 0 0 0 0

0 0 0 0 0 0 0

0 0 0 0 0 0 0

0 0 0 0 0 0 0

Matrix array populated with random values:

49 22 7 100 86 47 13

56 71 24 59 94 30 45

12 78 98 43 32 67 66

40 76 41 89 54 93 23

74 68 44 91 38 39 82

The sum of the elements of the array is: 1951

The sum of the elements per column are: [231, 315, 214, 382, 304, 276, 229]

The min value in the array Matrix is: 7

The min values per column are: [12, 22, 7, 43, 32, 30, 13]

49 56 12 40 74

22 71 78 76 68

7 24 98 41 44

100 59 43 89 91

86 94 32 54 38

47 30 67 93 39

13 45 66 23 82

Answer 1

import java.util.Random;
public class MyClass {
public static void fill(int matrix[][])
{
System.out.println("Initial Output:");
for(int i=0;i<5;i++)
{
for(int j=0;j<7;j++)
{
System.out.print(matrix[i][j]);
System.out.print(" ");
}
System.out.println();
}
Random rand = new Random();
for(int i=0;i<5;i++)
{
for(int j=0;j<7;j++)
{
matrix[i][j]=rand.nextInt(101)+1; //it produces random numbers between 1 and 100
}
}
System.out.println("Matrix array populated with random values:");
for(int i=0;i<5;i++)
{
for(int j=0;j<7;j++)
{
System.out.print(matrix[i][j]);
System.out.print(" ");
}
System.out.println();
}
}
public static void cummulative(int matrix[][])
{
int sum=0;
for(int i=0;i<5;i++)
{
for(int j=0;j<7;j++)
{
sum+=matrix[i][j];
}
}
System.out.println("The sum of the elements of the array is: "+sum);
}
public static void columnsum(int matrix[][])
{
int sum=0;
System.out.print("The sum of the elements per column are: [");
for(int i=0;i<7;i++)
{
for(int j=0;j<5;j++)
{
sum+=matrix[j][i];
}
System.out.print(sum);
if(i<6)
System.out.print(", ");
sum=0; //after finding the sum of each column re-initialize sum to 0
}
System.out.println("]");
}
public static void minval(int matrix[][])
{
int mini=matrix[0][0];
for(int i=0;i<5;i++)
{
for(int j=0;j<7;j++)
{
if(matrix[i][j]<mini)
mini=matrix[i][j];
}
}
System.out.println("The min value in the array Matrix is: "+mini);
}
public static void mincol(int matrix[][])
{
int mini=1000;
System.out.print("The min values per column are: [");
for(int i=0;i<7;i++)
{
for(int j=0;j<5;j++)
{
if(matrix[j][i]<mini)
mini=matrix[j][i];
}
System.out.print(mini);
if(i<6)
System.out.print(", ");
mini=1000; //after finding the minimum value of each column re-initialize mini to 1000
}
System.out.println("]");
}
public static void transpose(int matrix[][])
{
int [][]m_transpose = new int[7][5];
for(int i=0;i<5;i++) //store the transpose of matrix in m_transpose
{
for(int j=0;j<7;j++)
{
m_transpose[j][i]=matrix[i][j];
}
}
for(int i=0;i<7;i++)   
{
for(int j=0;j<5;j++)
{
System.out.print(m_transpose[i][j]);
System.out.print(" ");
}
System.out.println();
}
}
public static void main(String args[])
{
int [][]matrix= new int[5][7];
fill(matrix); //method to fill the array with random values
cummulative(matrix); //method to Compute the cumulative sum of the array matrix
columnsum(matrix); //method to print the cumulative sum of all the elements in each column
minval(matrix); //method to Compute the min value of the array matrix
mincol(matrix); //method to compute and print the minimum value in each column
transpose(matrix); //method to Create and copy the transpose of the array matrix into a new 2-dim array
}
  
}

output: