2d matrix multiplication
import java.util.Arrays;
import java.util.Scanner;
public class Matrix {
private static int counter =0;
private static Scanner scanner = new Scanner(System.in);
private int rawForArr1 =0 , columnForArr1=0, rawForArr2=0, ColumnForArr2=0;
public Matrix(){
}
public Matrix(int rawForArr1, int columnForArr1, int rawForArr2, int columnForArr2) {
this.rawForArr1 = rawForArr1;
this.columnForArr1 = columnForArr1;
this.rawForArr2 = rawForArr2;
ColumnForArr2 = columnForArr2;
}
public void sizeOfRawsAndColumns(int r1, int c1, int r2, int c2){
System.out.println("Enter numbers of raws for array#1");
r1=scanner.nextInt();
this.rawForArr1 =r1;
System.out.println("Enter numbers of columns for array#1");
c1=scanner.nextInt();
this.columnForArr1=c1;
System.out.println("Enter numbers of raws for array#2");
r2=scanner.nextInt();
this.rawForArr2 = r2;
System.out.println("Enter numbers of columns for array#2");
c2=scanner.nextInt();
this.ColumnForArr2 = c2;
checkIfMatrixIsValid(c1,r2,r1,c2);
}
public static void printValue(int[][] arr)
{
System.out.print(Arrays.deepToString(arr));
}
public static void checkIfMatrixIsValid(int c1,int r2,int r1, int c2)
{
while(c1 != r2)
{
System.out.println("The columns in the left array is not equal to the raw's in the right"+"\n"+
"array enter other values"+"\n"+
"enter a value and it will be assigned for valid Matrix");
Scanner scanner = new Scanner(System.in);
c1 = scanner.nextInt();
r2 = c1;
}
int [][] firstArr = initilizeMatrix(r1,c1);
int [][] secondArr = initilizeMatrix(r2,c2);
EnterElements(firstArr);
EnterElements(secondArr);
int[][] multplied =multiplieMatrix(firstArr,secondArr);
printValue(multplied);
}
public static int [][] initilizeMatrix(int n , int m)
{
int [][] newMatrix = new int[m][n];
return newMatrix;
}
public static int [][] multiplieMatrix(int [][] leftArr,int[][] rightArr){
int m = leftArr[0].length;
int n = rightArr.length;
int [][] sumOfMultiplie = new int[m][n];
int i=0,j=0,k=0;
int sum = 0 ;
for( i = 0 ; i < leftArr.length ; ++i)
{
for(j = 0 ; j < rightArr.length ; ++j)
{
for(k = 0 ; k < rightArr[0].length ; ++k)
{
sum+= leftArr[i][k]*rightArr[k][j];
}
sumOfMultiplie[i][j]=sum ;
sum=0;
}
}
return sumOfMultiplie ;
}
public static int[][] EnterElements(int[][] arr)
{
++counter;
if(counter==1){
System.out.println("Enter the elements for the left array"+'\n');
}else{
System.out.println("Enter the elements for the right array");
}
for(int i = 0 ; i < arr.length ; ++i)
{
for(int j = 0 ; j<arr.length ; ++j)
{
System.out.println("Enter element in raw #"+(i+1)+" column #"+(j+1));
arr[i][j] = scanner.nextInt();
}
}
return arr ;
}
}