Merge pull request 'added euler problem 2' (#2) from euler_problem_2 into main

Reviewed-on: https://baobabfruit.ddns.net/gitea/delano/project-euler/pulls/2

README.md

@@ -6,3 +6,10 @@ Several project euler problems solved in C++
 
 <p>If we list all the natural numbers below $10$ that are multiples of $3$ or $5$, we get $3, 5, 6$ and $9$. The sum of these multiples is $23$.</p>
 <p>Find the sum of all the multiples of $3$ or $5$ below $1000$.</p>
+
+
+# Euler problem 2 :
+
+<p>Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with $1$ and $2$, the first $10$ terms will be:
+$$1, 2, 3, 5, 8, 13, 21, 34, 55, 89, \dots$$</p>
+<p>By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.</p>

euler/euler/euler.cpp

@@ -4,12 +4,14 @@
 #include <iostream>
 #include <cassert> 
 #include "euler_p1.h"
+#include "euler_p2.h"
 
 
 
 void unit_tests() {
 
     assert(euler1(10) == 23);
+    assert(euler2(10) == 10);
 
     std::cout << "All tests passed! continues main." << std::endl;
 }
@@ -19,10 +21,16 @@ int euler_p1() {
     return res;
 }
 
+int euler_p2() {
+    int res = euler2(4000000);
+    return res;
+}
+
 int main()
 {
     unit_tests();
     
     std::cout << "the result for problem 1 = " << euler_p1() << std::endl;
+    std::cout << "the result for problem 2 = " << euler_p2() << std::endl;
 }
 

euler/euler/euler.vcxproj

@@ -129,9 +129,11 @@
   <ItemGroup>
     <ClCompile Include="euler.cpp" />
     <ClCompile Include="euler_p1.cpp" />
+    <ClCompile Include="euler_p2.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="euler_p1.h" />
+    <ClInclude Include="euler_p2.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

euler/euler/euler.vcxproj.filters

@@ -21,10 +21,16 @@
     <ClCompile Include="euler_p1.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="euler_p2.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="euler_p1.h">
       <Filter>Source Files</Filter>
     </ClInclude>
+    <ClInclude Include="euler_p2.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

euler/euler/euler_p2.cpp

@@ -0,0 +1,26 @@
+#include "euler_p2.h"
+
+/*
+Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
+1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
+By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
+*/
+
+int euler2(int limit) {
+
+	int current = 1;
+	int previous = 1;
+	int temp = 0;
+	int result = 0;
+
+	while (temp < limit) {
+		temp = current + previous;
+		previous = current;
+		current = temp;
+		if (temp % 2 == 0)
+		{
+			result += temp;
+		}
+	}
+	return result;
+}

euler/euler/euler_p2.h

@@ -0,0 +1,13 @@
+#pragma once
+#pragma once
+/**
+ * @brief Solves Euler problem 2: Even Fibonacci Numbers
+ *
+ * This function calculates the sum of all the even numbers in the fibonacchi sequence with the upper limit as close to given limit 
+ *
+ * @param limit The upper limit for the range to consider (should be positive).
+ * @return The sum of every even fibbonachi number lower then the limit.
+ *
+ * @note This function only works with positive integer inputs.
+ */
+int euler2(int limit);