These are my solutions to the Coderbyte challenges written in C++

FirstFactorial.cpp

#include <iostream>
using namespace std;

int FirstFactorial(int num) { 
	// set the limit to the number provided   
	int limit = num;
	for (int i = 1; i < limit; ++i) {
  		num = num * i;
	}
  	return num; 
}

int main() { 
  
	cout << FirstFactorial(4);
  	return 0;
}   

FirstReverse.cpp

#include <iostream>
using namespace std;
 
string FirstReverse(string str) {

	string rstr;
	
	// loop through characters in str
	for (int i = 0; i < str.size(); ++i) {
		// add characters to the front of rstr
		rstr = str[i] + rstr;
	}
	return rstr;
}

int main() { 
	cout << FirstReverse("reverse me if you can") << endl;
	// result: "nac uoy fi em esrever"
	return 0;
}

LongestWord.cpp

#include <iostream>
#include <vector>
#include <string>
using namespace std;

string LongestWord(string sen) {
	
	// create an empty vector
	vector<string> list;
	// create an empty string
	string word = "";

	for (int i = 0; i < sen.size(); ++i) {
		// if the letter is an alphabet add it to word
		if (isalpha(sen[i])) {
			word = word + (sen[i]);
		}
		// if it isn't a letter add word to list
		else {
			list.push_back(word);
			word = ""; // make word empty
		}
	}
	
	// if word is not empty then add it to list
	if (word != "") {
		list.push_back(word);
		word = ""; // make word empty
	}

	// create a string to store the longest word
	string longest = "";
	
	for (int i = 0; i < list.size(); ++i) {
		// compare length of two words
		if (longest.size() < list[i].size()) {
			longest = list[i];
		}
	}
 	return longest; 
}

int main() { 
  
  cout << LongestWord("Merry Christmas to one and all");
  // result: Christmas
  return 0;
    
}