merged

src/calc.cpp

@@ -2,10 +2,12 @@
 
 #include <stack>
 #include <stdexcept>
+#include <cmath>
 
 int plus(    int a, int b) { return a + b; }
 int minus(   int a, int b) { return a - b; }
 int multiply(int a, int b) { return a * b; }
+int power(   int a, int b) { return std::pow(a, b); }
 int modulo(  int a, int b) { return a % b; }
 int divide(  int a, int b) { 
   if(b == 0) {
@@ -35,6 +37,7 @@ int evaluate(const std::string &s) {
     case '-': change_stack_state(minus,    stack); break;
     case '*': change_stack_state(multiply, stack); break;
     case '/': change_stack_state(divide,   stack); break;
+    case '^': change_stack_state(power,    stack); break;
     case '%': change_stack_state(modulo,   stack); break;
     case '0'...'9': stack.push(c - '0'); break;
     default:

test/test.cpp

@@ -7,6 +7,12 @@ TEST_CASE( "some example calculations", "[calc]") {
   REQUIRE( evaluate("12+2-3*") == 3 );
 }
 
+TEST_CASE( "pow function works", "[calc]") {
+  REQUIRE( evaluate("22^") == 4 );
+  REQUIRE( evaluate("43^") == 64 );
+  REQUIRE( evaluate("11^") == 1);
+}
+
 TEST_CASE( "basic addition", "[calc]"){
   REQUIRE( evaluate("55+") == 10); 
   REQUIRE( evaluate("34+") == 7);