Example: Matrix Addition in C++

// Matrix Addition
#include <iostream>
#include <vector> // Required for std::vector

// Using namespace std for brevity as per template
using namespace std;

int main() {
    int rows, cols;

    // Step 1: Get dimensions from the user
    cout << "Enter the number of rows: ";
    cin >> rows;
    cout << "Enter the number of columns: ";
    cin >> cols;

    // Check for valid dimensions
    if (rows <= 0 || cols <= 0) {
        cout << "Matrix dimensions must be positive." << endl;
        return 1; // Indicate an error
    }

    // Declare three 2D vectors (matrices) using std::vector
    // matrix1 and matrix2 for input, sumMatrix for storing the result
    vector<vector<int>> matrix1(rows, vector<int>(cols));
    vector<vector<int>> matrix2(rows, vector<int>(cols));
    vector<vector<int>> sumMatrix(rows, vector<int>(cols));

    // Step 2: Input elements for Matrix 1
    cout << "\nEnter elements for Matrix 1:\n";
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            cout << "Enter element matrix1[" << i << "][" << j << "]: ";
            cin >> matrix1[i][j];
        }
    }

    // Step 3: Input elements for Matrix 2
    cout << "\nEnter elements for Matrix 2:\n";
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            cout << "Enter element matrix2[" << i << "][" << j << "]: ";
            cin >> matrix2[i][j];
        }
    }

    // Step 4: Perform matrix addition
    cout << "\nPerforming Matrix Addition...\n";
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            sumMatrix[i][j] = matrix1[i][j] + matrix2[i][j];
        }
    }

    // Step 5: Display the resultant sum matrix
    cout << "\nResultant Matrix (Sum):\n";
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            cout << sumMatrix[i][j] << " ";
        }
        cout << endl; // New line after each row
    }

    return 0;
}