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，如何进攻，可以担任中后卫和左后卫。
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.
上周阿森纳主帅温格承认他在寻找一名防守球员，这名球员可以打中卫和左后卫的位置。
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.
这位切尔西被租借出去的左后卫在30分钟的时候和本方的门将碰撞之后被担架抬出了场外。
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.
找到列表的中间节点,然后在这里将列表分解成两半，后端的拷贝，左部分的拷贝，右部分的拷贝。
麻省理工公开课 - 计算机科学及编程导论课程节选