add solution 2 in C++, tweak docs

README.rst

@@ -43,8 +43,8 @@ LivInTheLookingGlass’s Project Euler solutions
 |            | ``msvc``, |br|      |        |                   |
 |            | ``pcc``, ``tcc``    |        |                   |
 +------------+---------------------+--------+-------------------+
-| C++        | C++98+ in |br|      |  1     | |Cpi|             |
-|            | ``g++``, ``clang``, |        |                   |
+| C++        | C++98+ in |br|      |  2     | |Cpi|             |
+|            | ``gcc``, ``clang``, |        |                   |
 |            | ``msvc``            |        |                   |
 +------------+---------------------+--------+-------------------+
 | C#         | .NET 2+             |  6     | |C#i|             |

cplusplus/README.rst

@@ -155,4 +155,5 @@ Problems Solved
 ---------------
 
 -  ☒ `1 <./p0001.cpp>`__
+-  ☒ `2 <./p0002.cpp>`__
 

cplusplus/p0002.cpp

@@ -0,0 +1,45 @@
+/*
+Project Euler Problem 2
+
+Again, see Python implementation for a proof
+
+Problem:
+
+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.
+*/
+
+#ifndef EULER_P0002
+#define EULER_P0002
+#include <stdio.h>
+
+unsigned long long p0002() {
+    unsigned long long answer = 0,
+    a = 1, b = 2, t;
+    while (b < 4000000) {
+        // odd (1, 3, 13, 55, ...)
+        // odd (1, 5, 21, 89, ...)
+        // even (2, 8, 34, 144, ...)
+        answer += b;
+        for (unsigned char z = 0; z < 3; z++) {
+            t = b;
+            b = a + b;
+            a = t;
+        }
+    }
+    return answer;
+}
+
+#ifndef UNITY_END
+int main(int argc, char const *argv[])  {
+    unsigned long long answer = p0002();
+    printf("%llu\n", answer);
+    return 0;
+}
+#endif
+#endif

cplusplus/test_euler.py

@@ -21,6 +21,7 @@
 
 answers = {
     1: 233168,
+    2: 4613732,
 }
 
 # this is the set of problems where I have the right answer but wrong solution
@@ -78,7 +79,7 @@
     warn("Could not detect system architecture, defaulting to .exe")
     EXE_EXT = "exe"
 
-GCC_BINARY = environ.get('GCC_OVERRIDE', 'g++')
+GCC_BINARY = environ.get('GCC_OVERRIDE', 'gcc')
 AOCC_BINARY = environ.get('AOCC_OVERRIDE', 'clang')
 
 # compiler variables section
@@ -88,7 +89,7 @@
     for comp in environ['COMPILER_OVERRIDE'].upper().split(','):
         compilers.extend(f'{comp}+{std}' for std in STANDARDS)
 else:
-    if not (IN_TERMUX and GCC_BINARY == 'g++') and which(GCC_BINARY):  # Termux maps gcc->clang
+    if not (IN_TERMUX and GCC_BINARY == 'gcc') and which(GCC_BINARY):  # Termux maps gcc->clang
         compilers.extend(f'GCC+{std}' for std in STANDARDS)
     if which('clang'):
         if b'AOCC' in check_output(['clang', '--version']):

docs/cplusplus/p0002.rst

@@ -0,0 +1,8 @@
+C++ Implementation of Problem 2
+===============================
+
+View source code `here on GitHub! <https://github.com/LivInTheLookingGlass/Euler/blob/master/cplusplus/p0002.cpp>`_
+
+.. literalinclude:: ../../cplusplus/p0002.cpp
+   :language: C++
+   :linenos:

docs/index.rst

@@ -102,7 +102,7 @@ This project is divided into several Makefiles, connected by a root Makefile whi
 +-----------+------+------+------+------+------+------+
 |:prob:`1`  |  |d| |  |d| |  |d| |  |d| |  |d| |  |d| |
 +-----------+------+------+------+------+------+------+
-|:prob:`2`  |  |d| |      |  |d| |  |d| |  |d| |  |d| |
+|:prob:`2`  |  |d| |  |d| |  |d| |  |d| |  |d| |  |d| |
 +-----------+------+------+------+------+------+------+
 |:prob:`3`  |  |d| |      |      |      |  |d| |  |d| |
 +-----------+------+------+------+------+------+------+