translated exception messages to make output uniform

main.cpp

@@ -28,7 +28,7 @@ int multiply(int a, int b) {return a * b;}
  */
 int divide(int a, int b) {
 	if (b == 0) {
-		throw std::invalid_argument("Division durch 0!");
+		throw std::invalid_argument("Tried to divide by 0.");
 	}
 	return a / b;
 }
@@ -56,15 +56,15 @@ int evaluate(const std::string &s) {
 					stack.pop();
 					stack.push(iter->second(b, a));
 				} else {
-					throw std::invalid_argument("Ungueltige Sonderzeichen");
+					throw std::invalid_argument("Invalid character found.");
 				}
 			} else {
-				throw std::invalid_argument("Ungueltige Anzahl an Zahlen");
+				throw std::invalid_argument("Invalid number of digits.");
 			}
 		}
 	}
 	if (stack.size() > 1 || stack.size() == 0) {
-		throw std::invalid_argument("Ungueltige Eingabe");
+		throw std::invalid_argument("Invalid input.");
 	}
 	return stack.top();
 }