Added the first problems for ProjectEuler.net

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2018-09-25 23:17:01 -04:00
parent 2f34971b55
commit 3fe2423e9a
3 changed files with 96 additions and 0 deletions

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ProjectEuler/Problem1.m Normal file
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%ProjectEuler/Problem1.m
%This is a script to answer Problem 1 for Project Euler
%What is the sum of all the multiples of 3 or 5 that are less than 1000
%Setup your variables
fullSum = 0; %To hold the sum of all the numbers
numbers = 0; %To hold all of the numbers
counter = 0; %The number. It must stay below 1000
while(counter < 1000)
%See if the number is a multiple of 3
if(mod(counter, 3) == 0)
numbers(end + 1) = counter;
%See if the number is a multiple of 5
elseif(mod(counter, 5) == 0)
numbers(end + 1) = counter;
end
%Increment the number
++counter;
end
%When done this way it removes the possibility of duplicate numbers
fullSum = sum(numbers);
fullSum

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ProjectEuler/Problem2.m Normal file
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%ProjectEuler/Problem2.m
%This is a script to answer Problem 2 for Project Euler
%The sum of the even Fibonacci numbers less than 4,000,000
%Setup your Variables
fib = [1, 1, 2]; %Holds the Fibonacci numbers
currentFib = fib(end) + fib(end - 1); %The current Fibonacci number to be tested
evenFib = [2]; %A subset of the even Fibonacci numbers
finalSum = 0;
while(currentFib < 4000000)
%Add the number to the list
fib(end + 1) = currentFib;
%If the number is even add it to the even list as well
if(mod(currentFib, 2) == 0)
evenFib(end + 1) = currentFib;
end
%Set the next Fibonacci
currentFib = fib(end) + fib(end - 1);
end
finalSum = sum(evenFib);
finalSum

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%ProjectEuler/Problem3.m
%This is a script to answer Problem 3 for Project Euler
%The largest prime factor of 600851475143
%Setup your variables
number = 600851475143; %The number we are trying to find the greatest prime factor of
primeNums = []; %A list of prime numbers. Will include all prime numbers <= number
factors = []; %For the list of factors of number
tempNum = number; %Used to track the current value if all of the factors were taken out of number
%number = 16; %Used for a test case
%Get the prime numbers up to sqrt(number). If it is not prime there must be a value <= sqrt
primeNums = primes(sqrt(number));
%Setup the loop
counter = 1;
%Start with the lowest number and work your way up. When you reach a number > size(primeNums) you have found all of the factors
while(counter <= size(primeNums)(2))
%Divide the number by the next prime number in the list
answer = (tempNum/primeNums(counter));
%If it is a whole number add it to the factors
if(mod(answer,1) == 0)
factors(end + 1) = primeNums(counter);
%Set tempNum so that it reflects number/factors
tempNum = tempNum / primeNums(counter);
%Keep the counter where it is in case a factor appears more than once
%Get the new set of prime numbers
primeNums = primes(sqrt(tempNum));
else
%If it was not an integer increment the counter
++counter;
end
end
%When the last number is not divisible by a prime number it must be a prime number
factors(end + 1) = tempNum;
%Remove the variables
clear counter;
clear tempNum;
clear answer;
clear number;
clear primeNums;
%Print the answer
max(factors)