Answer to Question #294619 in C++ for Yaku

Question

3. Write a C++ recursive function that takes a string and reverse the string.

4. Write a C++ recursive function that takes an array of words and returns an array

that contains all the words capitalized.

5. Write a linear search C++ program that searches for a number in a two

dimensional array.

6. What is each on the following functions going to achieve:

a)

int fun(int x, int y)

{

if (x == 0)

return y;

else

return fun(x - 1, x + y);

}

b)

int fun(int a, int t)

{

if (a == 0)

return t;

t = (t * 10) + (a % 10);

return fun(a / 10, t);

}

Answer 1

6.a: this function finds sum y and all natural numbers with x inclusive

(for example, x = 3, y = 5. The result of function is 1 + 2 + 3 + 5 = 11)

6.b: this function ascribes the inverted a to t at the back

(for example, a = 1092, y = 532. The result of function is 5322901)

# include <string>
# include <cctype>
# include <vector>


std::string reverse(std::string input) {
	if (!input.empty()) {
		auto buff = input.back();
		input.pop_back();
		return buff + reverse(input);
	}
	else return "";
}


std::vector<std::string> capitalize(std::vector<std::string> input) {
	if (input.size() > 1) {
		std::string buf = static_cast<char>(std::toupper(input.back()[0])) + input.back();
		input.pop_back();
		std::vector<std::string> output(capitalize(input));
		output.push_back(buf);
		return output;
	}
	else {
		input[0][0] = static_cast<char>(std::toupper(input[0][0]));
		return input;
	}
}


std::pair<int, int> linear_search(std::vector<std::vector<int>> mass, int desired_num) {
	int i0, i1;
	for (i0 = 0; i0 < mass.size(); ++i0)
		for (i1 = 0; i1 < mass[i0].size(); ++i1)
			if (mass[i0][i1] == desired_num) return std::pair<int, int>(i0, i1);
	return std::pair<int, int>(i0 + 1, i1 + 1);
}