//ProjectEuler/C/Problem2.c
//Matthew Ellison
// Created: 03-11-19
//Modified: 03-28-19
//The sum of the even Fibonacci numbers less than 4,000,000
//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/myHelpers
//This program needs the -lm flag to compile
/*
	Copyright (C) 2019  Matthew Ellison

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/


#include <stdio.h>
#include <inttypes.h>
#include "Stopwatch.h"
#include "Algorithms.h"
#include "DynamicInt64Array.h"

const uint64_t TOP_NUM = 4000000;	//Holds the largest number that we are looking for


int main(){
	//Create a timer for the algorithm
	struct Stopwatch timer;
	initStopwatch(&timer);

	uint64_t fullSum = 0;	//Holds the sum of all the numbers

	//Start the timer
	startStopwatch(&timer);

	//Get all of the fibonacci numbers < TOP_NUM
	struct DynamicInt64Array fibList = getAllFib(TOP_NUM - 1);

	//Step through the sum of all the elements to find the even numbers and add them to the running sum
	for(uint64_t cnt = 0;cnt < fibList.size;++cnt){
		//Get the current number
		int64_t num = getDynamicInt64Array(&fibList, cnt);

		//If the number is even add it to the sum
		if((num % 2) == 0){
			fullSum += num;
		}
		//Otherwise ignore it
	}

	//Stop the timer
	stopStopwatch(&timer);
	char* timerStr = getStrStopwatch(&timer);

	//Print the results
	printf("The sum of the even Fibonacci numbers less than %ld is %ld\n", TOP_NUM, fullSum);
	printf("It took %s to run this algorithm\n", timerStr);

	//Free the memory taken by the program
	destroyDynamicInt64Array(&fibList);
	free(timerStr);
	timerStr = NULL;

	return 0;
}

/* Results:
The sum of the even Fibonacci numbers less than 4000000 is 4613732
It took 52.000 microseconds to run this algorithm
*/