Java Program to Multiply two Matrices of any size
Given two matrices A and B of any size, the task to multiply them in Java.
Examples:
Input: A[][] = {{1, 2},
{3, 4}}
B[][] = {{1, 1},
{1, 1}}
Output: {{3, 3},
{7, 7}}
Input: A[][] = {{2, 4},
{3, 4}}
B[][] = {{1, 2},
{1, 3}}
Output: {{6, 16},
{7, 18}}
Approach:
- Take the two matrices to be multiplied
- Check if the two matrices are compatible to be multiplied
- Create a new Matrix to store the product of the two matrices
- Traverse each element of the two matrices and multiply them. Store this product in the new matrix at the corresponding index.
- Print the final product matrix
Below is the implementation of the above approach:
// Java program to multiply two square matrices. import java.io.*; class GFG { // Function to print Matrix static void printMatrix(int M[][], int rowSize, int colSize) { for (int i = 0; i < rowSize; i++) { for (int j = 0; j < colSize; j++) System.out.print(M[i][j] + " "); System.out.println(); } } // Function to multiply // two matrices A[][] and B[][] static void multiplyMatrix( int row1, int col1, int A[][], int row2, int col2, int B[][]) { int i, j, k; // Print the matrices A and B System.out.println("\nMatrix A:"); printMatrix(A, row1, col1); System.out.println("\nMatrix B:"); printMatrix(B, row2, col2); // Check if multiplication is Possible if (row2 != col1) { System.out.println( "\nMultiplication Not Possible"); return; } // Matrix to store the result // The product matrix will // be of size row1 x col2 int C[][] = new int[row1][col2]; // Multiply the two marices for (i = 0; i < row1; i++) { for (j = 0; j < col2; j++) { for (k = 0; k < row2; k++) C[i][j] += A[i][k] * B[k][j]; } } // Print the result System.out.println("\nResultant Matrix:"); printMatrix(C, row1, col2); } // Driver code public static void main(String[] args) { int row1 = 4, col1 = 3, row2 = 3, col2 = 4; int A[][] = { { 1, 1, 1 }, { 2, 2, 2 }, { 3, 3, 3 }, { 4, 4, 4 } }; int B[][] = { { 1, 1, 1, 1 }, { 2, 2, 2, 2 }, { 3, 3, 3, 3 } }; multiplyMatrix(row1, col1, A, row2, col2, B); }} |
Output:
Matrix A: 1 1 1 2 2 2 3 3 3 4 4 4 Matrix B: 1 1 1 1 2 2 2 2 3 3 3 3 Resultant Matrix: 6 6 6 6 12 12 12 12 18 18 18 18 24 24 24 24
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