Question

How to calculate the frequency of each letter in a string with C++

Answer 1

#include <iostream>

int main()
{
	std::string s = "c c++ c# java python";
	int ascii[256] = { 0 };

	for (int i = 0; s[i]; i++)
		ascii[s[i]]++;

	for (int i = 0; i < 256; i++)
	{
		if (ascii[i])
			std::cout << (char)i << " : " << ascii[i] << std::endl;
	}

	return 0;
}



/*
run:

  : 4
# : 1
+ : 2
a : 2
c : 3
h : 1
j : 1
n : 1
o : 1
p : 1
t : 1
v : 1
y : 1

*/

 

70+ SQL courses for beginners and professionals

Answer 2

#include <iostream>
#include <map>

int main()
{
	std::string s = "c c++ c# java python";
	std::map<char, std::size_t> frequency;

	for (auto ch : s)
	{
		if (frequency.find(ch) == frequency.end())
			frequency[ch] = 1;
		else
			frequency[ch]++;
	}

	for (auto element : frequency)
		std::cout << element.first << " : " << element.second << std::endl;

	return 0;
}



/*
run:

  : 4
# : 1
+ : 2
a : 2
c : 3
h : 1
j : 1
n : 1
o : 1
p : 1
t : 1
v : 1
y : 1

*/

 

70+ SQL courses for beginners and professionals