Roll Left, Roll Right

while !isBlocked {
    moveForward()
    if isOnGem {
        collectGem()
        turnRight()
        moveForward()
        collectGem()
    } else if isOnClosedSwitch && isBlockedLeft {
        toggleSwitch()
        turnRight()
    } else if isOnClosedSwitch && isBlockedRight {
        toggleSwitch()
        turnLeft()
        moveForward()
        toggleSwitch()
    } else if isBlocked && isBlockedRight {
        turnLeft()
    }
}

I ran this code and it didn’t solve the puzzle.

Commands ended there.

Yeah. That solution won’t work. Here’s what I came up with. I like this one because there are no repeated commands, just one collectGem(), one toggleSwitch(), one moveForward(), one turnLeft(), one turnRight(). Makes it easier to read for me and fewer lines of code:

while !isOnOpenSwitch {
    while !isBlocked {
        if isOnGem {
            collectGem()
        }
        if isOnClosedSwitch {
            toggleSwitch()
        }
        moveForward()
    }
    if isBlockedRight || isOnClosedSwitch {
        turnLeft()
    }
    if isBlockedLeft || isOnGem {
        turnRight()
    }
} 

So funny how many options there are to solve this puzzle! This one took me so long to figure out (more than what I'd like to admit), and I felt oddly relieved after I saw the code worked.

Here's what I came up with:

func navAround() {
    if !isBlocked {
        while isOnGem || isOnClosedSwitch {
            if isOnGem {
                collectGem()
            } else if isOnClosedSwitch {
                toggleSwitch()
            }
        }
        moveForward()
    } else if isBlockedLeft && isBlocked {
        turnRight()
    } else {
        turnLeft()
    }
}

while !isOnOpenSwitch {
    navAround()
}

Cheers!