我们学习过了初始化，现在来到训练的阶段了。
执行代码如下：
let expert = Expert()
expert.turnLeft()
expert.turnLeft()
for i in 1 ... 2 {
expert.moveForward()
}
expert.turnLockDown()
var gemNum = 0
while gemNum < 6 {
if expert.isOnGem{
expert.collectGem()
gemNum += 1
}else if expert.isBlocked {
expert.turnLeft()
expert.turnLeft()
}else if !expert.isBlockedLeft && !expert.isBlockedRight {
expert.turnLeft()
expert.moveForward()
}else{
expert.moveForward()
}
}
执行后的结果：
