public function testCalculate()
{
$rpn = new RPN();
$expression = array('2', '1', '+', '3', '*', '4', '7', '4', '+', '*', '-');
$result = $rpn->calculate($expression);
$this->assertEquals(-35, $result);
$expression = array('3', '4', '+', '8', '3', '2', '*', '*', '+');
$result = $rpn->calculate($expression);
$this->assertEquals(55, $result);
$expression = array('2', '3', '+', '5', '1', '*', '-');
$result = $rpn->calculate($expression);
$this->assertEquals(0, $result);
$expression = array('1', '3', '*', '5', '2', '*', '+', '3', '-');
$result = $rpn->calculate($expression);
$this->assertEquals(10, $result);
$expression = array('2', '3', '+', '2', '1', '-', '*', '3', '+');
$result = $rpn->calculate($expression);
$this->assertEquals(8, $result);
$expression = array('3', '5', '-');
$result = $rpn->calculate($expression);
$this->assertEquals(-2, $result);
$expression = array('0', '1', '-', '2', '1', '-', '*');
$result = $rpn->calculate($expression);
$this->assertEquals(-1, $result);
}
private function calculateRPN($rpnData)
{
$rpn = new RPN();
return $rpn->calculate($rpnData);
}
