Practice Problems on Arrays and Strings in C++

#include <iostream>Copy Code
int main() {
// Declare variables to store the two numbers
double num1, num2;

// Input the two numbers
std::cout << "Enter the first number: ";
std::cin >> num1;

std::cout << "Enter the second number: ";
std::cin >> num2;

// Perform addition
double sum = num1 + num2;

// Display the result
std::cout << "Sum: " << sum << std::endl;

return 0;
}

#include <iostream>Copy Code
#include <string>

int main() {
// Declare two strings
std::string str1, str2;

// Input two strings
std::cout << "Enter the first string: ";
std::getline(std::cin, str1);

std::cout << "Enter the second string: ";
std::getline(std::cin, str2);

// Concatenate strings using the + operator
std::string result1 = str1 + str2;

// Concatenate strings using the append() member function
std::string result2 = str1;
result2.append(str2);

// Display the concatenated strings
std::cout << "Concatenated string using + operator: " << result1 << std::endl;
std::cout << "Concatenated string using append(): " << result2 << std::endl;

return 0;
}

#include <iostream>Copy Code
const int MAX_SIZE = 10;

int main() {
int matrix[MAX_SIZE][MAX_SIZE], transposed[MAX_SIZE][MAX_SIZE];
int rows, cols;

// Input the dimensions of the matrix
std::cout << "Enter the number of rows in the matrix: ";
std::cin >> rows;

std::cout << "Enter the number of columns in the matrix: ";
std::cin >> cols;

// Input the elements of the matrix
std::cout << "Enter the elements of the matrix:" << std::endl;
for (int i = 0; i < rows; ++i) {
for (int j = 0; j < cols; ++j) {
std::cout << "Enter element at position (" << i + 1 << ", " << j + 1 << "): ";
std::cin >> matrix[i][j];
}
}

// Calculate and display the transpose of the matrix
std::cout << "\nOriginal Matrix:" << std::endl;
for (int i = 0; i < rows; ++i) {
for (int j = 0; j < cols; ++j) {
std::cout << matrix[i][j] << " ";
}
std::cout << std::endl;
}

// Calculate and display the transpose of the matrix
std::cout << "\nTranspose of the Matrix:" << std::endl;
for (int j = 0; j < cols; ++j) {
for (int i = 0; i < rows; ++i) {
std::cout << matrix[i][j] << " ";
}
std::cout << std::endl;
}

return 0;
}

#include <iostream>Copy Code
#include <cmath>
#include <vector>
#include <numeric>

int main() {
int n;
std::cout << "Enter the number of elements: ";
std::cin >> n;

std::vector<double> numbers(n);
std::cout << "Enter the elements:\n";
for (double& num : numbers) {
std::cin >> num;
}

double mean = std::accumulate(numbers.begin(), numbers.end(), 0.0) / n;
double deviation = sqrt(std::accumulate(numbers.begin(), numbers.end(), 0.0,
[mean](double acc, double num) { return acc + pow(num - mean, 2.0); }) / n);

std::cout << "Standard Deviation: " << deviation << std::endl;

return 0;
}