left half back

基本解释

He knows how to defend, how to attack and can play either centre-half or left-back.
他知道如何防守，如何進攻，可以擔任中後衛和左後衛。
bbs.arsenal.com.cn
Manager Arsene Wenger admitted last week that he was searching for a defender capable of playing at both centre-half and left-back.
上周阿森納主帥溫格承認他在尋找一名防守球員，這名球員可以打中衛和左後衛的位置。
bbs.arsenal.com.cn
Chelsea's on-loan left-back was stretchered off after half-an-hour following a collision with his own goalkeeper. It has been reported that he suffered ankle ligament damage.
這位切爾西被租借出去的左後衛在30分鍾的時候和本方的門將碰撞之後被擔架擡出了場外。
www.chelsea.net.cn

It's says find the mid-point and split the list in half. Copy of the back end, sorry, copy of the left side, copy of the right side.
找到列表的中間節點,然後在這裡將列表分解成兩半，後耑的拷貝，左部分的拷貝，右部分的拷貝。
麻省理工公開課 - 計算機科學及編程導論課程節選