Example: Matrix Addition in C++

// Matrix Addition
#include <iostream>
#include <vector> // For dynamic arrays

using namespace std;

int main() {
    int rows1, cols1, rows2, cols2;

    // Step 1: Get dimensions for the first matrix
    cout << "Enter number of rows for matrix 1: ";
    cin >> rows1;
    cout << "Enter number of columns for matrix 1: ";
    cin >> cols1;

    // Step 2: Get dimensions for the second matrix
    cout << "Enter number of rows for matrix 2: ";
    cin >> rows2;
    cout << "Enter number of columns for matrix 2: ";
    cin >> cols2;

    // Step 3: Check if matrices can be added
    if (rows1 != rows2 || cols1 != cols2) {
        cout << "Matrices cannot be added! Dimensions must be the same." << endl;
        return 1; // Indicate an error
    }

    // Declare matrices using std::vector for dynamic sizing
    // matrix1 and matrix2 store the input matrices
    // sumMatrix will store the result of the addition
    vector<vector<int>> matrix1(rows1, vector<int>(cols1));
    vector<vector<int>> matrix2(rows2, vector<int>(cols2));
    vector<vector<int>> sumMatrix(rows1, vector<int>(cols1));

    // Step 4: Input elements for matrix 1
    cout << "\nEnter elements for matrix 1:" << endl;
    for (int i = 0; i < rows1; ++i) {
        for (int j = 0; j < cols1; ++j) {
            cout << "Enter element a[" << i << "][" << j << "]: ";
            cin >> matrix1[i][j];
        }
    }

    // Step 5: Input elements for matrix 2
    cout << "\nEnter elements for matrix 2:" << endl;
    for (int i = 0; i < rows2; ++i) {
        for (int j = 0; j < cols2; ++j) {
            cout << "Enter element b[" << i << "][" << j << "]: ";
            cin >> matrix2[i][j];
        }
    }

    // Step 6: Perform matrix addition
    // Iterate through each row
    for (int i = 0; i < rows1; ++i) {
        // Iterate through each column
        for (int j = 0; j < cols1; ++j) {
            // Add corresponding elements and store in sumMatrix
            sumMatrix[i][j] = matrix1[i][j] + matrix2[i][j];
        }
    }

    // Step 7: Display the resulting sum matrix
    cout << "\nResultant Matrix (Sum):" << endl;
    for (int i = 0; i < rows1; ++i) {
        for (int j = 0; j < cols1; ++j) {
            cout << sumMatrix[i][j] << " ";
        }
        cout << endl; // Move to the next line after each row
    }

    return 0;
}