C++ Vector Exercises: Create an n x n matrix by taking an integer (n)

Last update on December 20 2024 12:32:39 (UTC/GMT +8 hours)

Write a C++ program to create an n x n matrix by taking an integer (n) as input from the user.

Sample Data:
(2) ->
[ [ 2, 2],
[2, 2]]
(5) ->
[ [ 5,5,5,5,5],
[ 5,5,5,5,5],
[ 5,5,5,5,5],
[ 5,5,5,5,5],
[ 5,5,5,5,5]]

Sample Solution-1:

C++ Code:

#include <algorithm>    // Including the Algorithm Library for certain functions like sort
#include <iostream>     // Including the Input/Output Stream Library
#include <vector>       // Including the Vector Library for using vectors

using namespace std;    // Using the Standard Namespace

// Function to create an n x n matrix filled with values equal to 'n'
std::vector<std::vector<int>> test(int n) {
  std::vector<int> t(n, n); // Creating a vector 't' of size 'n' filled with 'n'
  std::vector<std::vector<int>> arr(n, t); // Creating a 2D vector 'arr' of size 'n x n' filled with vector 't'
  return arr; // Returning the 'n x n' matrix
}

// Main function
int main() {
  int n;
  cout << "Input an integer value: ";
  cin >> n; // Taking user input for the size of the matrix

  std::vector<std::vector<int>> result = test(n); // Calling the test function to create the 'n x n' matrix
  cout << "Create an n x n matrix by said integer:\n";

  // Print the elements of the created 'n x n' matrix
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++)
      printf("%d ", result[i][j]); // Printing each element of the matrix
    printf("\n"); // Moving to the next row after each inner loop completes
  }
}

Sample Output:

Input: 2
Input an integer value: Create an n x n matrix by said integer:
2 2 
2 2

Flowchart:

Sample Solution-2:

C++ Code:

#include <algorithm>    // Including the Algorithm Library for certain functions like sort
#include <iostream>     // Including the Input/Output Stream Library
#include <vector>       // Including the Vector Library for using vectors

using namespace std;    // Using the Standard Namespace

// Function to create an n x n matrix filled with values equal to 'n'
std::vector<std::vector<int>> test(int n) {
  std::vector<int> vect_data(n, n); // Creating a vector 'vect_data' of size 'n' filled with 'n'
  std::vector<std::vector<int>> result(n, vect_data); // Creating a 2D vector 'result' of size 'n x n' filled with vector 'vect_data'
  return result; // Returning the 'n x n' matrix
}

// Main function
int main() {
  int n;
  cout << "Input an integer value: ";
  cin >> n; // Taking user input for the size of the matrix

  std::vector<std::vector<int>> result = test(n); // Calling the test function to create the 'n x n' matrix
  cout << "Create an n x n matrix by said integer:\n";

  // Print the elements of the created 'n x n' matrix
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++)
      printf("%d ", result[i][j]); // Printing each element of the matrix
    printf("\n"); // Moving to the next row after each inner loop completes
  }
}

Sample Output:

Input: 5
Input an integer value: Create an n x n matrix by said integer:
5 5 5 5 5 
5 5 5 5 5 
5 5 5 5 5 
5 5 5 5 5 
5 5 5 5 5

Flowchart:

C++ Code Editor:

Contribute your code and comments through Disqus.

Previous C++ Exercise: Vector elements smaller than its adjacent neighbours.
Next C++ Exercise: Capitalize the first character of each vector element.