How to Multiply 2 Martices using Cpp. What is logic ?

Question

I am finding it difficult to create a cpp program that can multiply as many number of matrices as many user wants with desired rows and columns, any help will be appreciated.

Answer 1

Thanks for advice, ill do more research on it

Answer 2

http://www.programmingsimplified.com/c-program-multiply-matrices

Answer 3

First I would look at how you multiply two matrices by hand. Look at the pattern it has and try to convert it over to an algorithm.

For example

|4 5.| | 5 2|
|1 2.| | 3. 4|

The first element of the new matrix C will be (4 × 5) + (5 × 3), or (A [0][0] × B [0][0]) + (A [0][1] * B [1][0]).

Now look at the rest of the multiplications (I'll leave that to you, check online on matrix multiplication if you get stuck). NOTE, only certain matrices can be multiplied as well, for example a 1x3 and a 1×3 cannot be multiplied but a 1×3 and a 3×1 can. If the columns of matrix one and the rows of matrix two are the same then you can do it.

Answer 4

To multiply an m×n matrix by an n×p matrix, the n must be the same, and the result is an m×p matrix.
The time complexity of this c program is O(n3).
For Example: If we multiply a 2×4 matrix and a 4×3 matrix, then the product matrix will be a 2×3 matrix.

Here is the code snippet to multiply two matrices.
/* Multiply both matrices */
for(i = 0; i < rows1; i++){
for(j = 0; j < rows2; j++){
for(k = 0; k < cols2; k++){
productMatrix[i][j] += firstMatrix[i][k]*secondMatrix[k][j];
}
}
}
You can check full c/C++ program here
http://www.techcrashcourse.com/2015/03/c-program-for-matrix-multiplication.html
http://www.techcrashcourse.com/2017/01/cpp-program-to-multiply-two-matrices.html