//============================================================================
// Name        : Looping.cpp
// Author      : Chandan R. Rupakheti
// Version     : 1.0
// Copyright   : You are free to copy, modify and redistribute this program without attribution.
// Description : Examples of Counter Controlled and Event Controlled Loops. 
//               Code snippets are mostly borrowed from the EE261 textbook with slight modifications.
//============================================================================

#include <iostream>
#include <fstream>
#include <math.h>
using namespace std;


void findFactorial()
{
	cout << "============================================================================" << endl;
	cout << "Factorial Computation" << endl;
	cout << "============================================================================" << endl;

	// Read a number
	int n;
	cout << "Input a number: ";
	cin >> n;

	int factorial = 1;
	int counter = 1;
	while (counter <= n){
		factorial *= counter;
		counter++;
	}

	cout << "Factorial: " << factorial << endl;
}



void countSpace() {
	cout << "============================================================================" << endl;
	cout << "Space counter in a line" << endl;
	cout << "============================================================================" << endl;

	cout << "Please enter a line: ";
	int spaces = 0;
	char data;
	cin.get(data);
	while(data != '\n'){
		if(data == ' ')
			++spaces;
		cin.get(data);
	}

	cout << "Number of spaces in your input: " << spaces << endl;
}



void guessSquareRoot() {
	cout << "============================================================================" << endl;
	cout << "Square Root Guesser" << endl;
	cout << "============================================================================" << endl;

	cout << "Please enter a number: ";
	float square;
	cin >> square;

	float guess = square / 4.0;
	bool goodEnough = false;
	while (goodEnough){
		guess = (square/guess + guess)/2.0;
		cout << guess << endl;
		goodEnough = fabs(square-guess*guess) < 0.001;
	}

	cout << "My square root guess is: " << guess;
}



void sumFiveOddNums() {
	cout << "============================================================================" << endl;
	cout << "Sum of odd numbers computation" << endl;
	cout << "============================================================================" << endl;

	int sum = 0;
	int number = 0;
	int count =0;

	bool lessThanFive = true;
	while (lessThanFive){
		// Read the number
		cout << "Enter a number: ";
		cin >> number;

		// Check if the number is odd
		if (number % 2 == 1){
			count++;
			sum = sum + number;
			lessThanFive = count < 5;
		}
		else {
			cout << "Discarding " << number << "! It is a even number!" << endl;
		}
	}

	cout << "Sum: " << sum << endl;
}


// We extended the digrams frequency analyzer problem to trigrams in class
void trackingPreviousValue() {
	cout << "============================================================================" << endl;
	cout << "Trigrams frequency analyzer." << endl;
	cout << "============================================================================" << endl;

	ifstream inFile;
	inFile.open("data.txt");

	// Check if inFile is in error state or not
	if(!inFile) {
		cout << "ERROR: Unable to open file!" << endl;
		return;
	}

	// Digram characters to be checked
	char firstChar;
	char secondChar;
	char thirdChar;

	cout << "Please enter an english trigram: ";
	cin.get(firstChar);
	cin.get(secondChar);
	cin.get(thirdChar);

	char prevChar;
	char currChar;
	char nextChar;
	inFile.get(prevChar);
	inFile.get(currChar);
	inFile.get(nextChar);

	int count = 0;
	while (inFile){
		if(prevChar == firstChar && currChar == secondChar && nextChar == thirdChar)
			count++;
		prevChar = currChar;
		currChar = nextChar;
		inFile.get(nextChar);
	}

	cout << "Frequency of trigram [" << firstChar << secondChar << thirdChar << "] is: " << count;
}


void nestedLoops() {
	cout << "============================================================================" << endl;
	cout << "Nested Loop Example" << endl;
	cout << "============================================================================" << endl;

	cout << "Enter number of stars: ";
	int starCount;
	cin >> starCount;
	cout << "Press 'Q' to end program!" << endl;

	while (cin){
		cout << endl;
	    int loopCount = 1;
	    while (loopCount <= starCount) {
	           cout << '*';
	           a = loopCount++;
	           cout << loopCount;
	     }
	    cout << endl << endl;

		cout << "Press 'Q' to end program!" << endl;
		cout << "Enter number of stars: ";
		cin >> starCount;
	}
	cout << "Goodbye!" << endl;
}


int main()
{
	findFactorial();
//	countSpace();
//	guessSquareRoot();
//	sumFiveOddNums();
//	trackingPreviousValue(); // Try checking freq(the) > freq(ing) > freq(and)
//	nestedLoops();

	return 0;
}