13.cpp

#include <iostream>
#include <string>

using namespace std;

void triangle(int t){
  int i, x;
  for (i = 0; i <= t; i++){
    cout << endl;
    for (x = 0; x < i; x++){
      cout << "T";
    }
  }
  cout << endl;
  for (i = 0; i < t; i++){
    for (x = 0; x < t-i-1; x++){
    cout << "T";
    }
  cout << endl;
  }
}

int exponential(long int c, long int d){
	long int i, result;
	result = c;
	for (i = 1; i < d; i++) {
		result = result * c;
	}
	return result;
}

int fib (int x){
  int y;
  if (x>=2){
    y=fib(x-1) + fib (x-2);
    return y;
  }
  else
  if (x==1)
  return 1;
  else
  return 0;
}

void checkPal(string word){
  int i;
  for(i=0; i<(word.size()/2); i++){
    if(word[i]!=(word[word.size()-1-i]))
    break;
  }
  if(i==(word.size()/2))
  cout << word <<" is a palindrome"<<endl;
  else
  cout << word <<" is NOT a palindrome"<<endl;
}

int main (){
  int menu;
  cout << "Here is the compilation of the exam programs." << endl << endl;
  cout << "1. Creat a triangle with T's " << endl << endl;
  cout << "2. Elevate to a power a number" << endl << endl;
  cout << "3. Fibonacci " << endl << endl;
  cout << "4. Palindrome" << endl << endl;
  cout << "Please type the number of the option:";
  cin >> menu;
  switch (menu) {
    case 1:
    int t;
    cout << "Type the size of the triange: ";
    cin >> t;
    triangle(t);
    break;

    case 2:
    int a, b;
  	long int to;
  	cout << "Type number you want to raise: ";
  	cin >> a;
  	cout << "Type the exponential number: ";
  	cin >> b;
  	to = exponential(a,b);
  	cout << "Your result is: " << to << endl;
    break;

    case 3:
    int x, ans;
    cout << "This program calculates the Fibonacci number that you want."<<endl;
    cout << "Give me a number: ";
    cin >> x;
    ans = fib (x);
    cout << "The Fibonacci number is: "<<ans<<endl;
    break;

    case 4:
    string word;
    cout << "What word you want to check (please enter all in lower case): ";
    cin >> word;
    checkPal(word);
    break;
  }

}