程序设计与算法基础课件.pptVIP

程序设计与算法基础(2) 潘爱民 2006/9/25 提纲 基本数据结构——list 基本数据结构——stack 基本数据结构——queue list 单链表(singly linked list) 双链表(doubly linked list) List的性质 在两端插入元素非常快速、简单 查找中间元素效率不高 SkipList 查找过程 构造和维护过程 * 建议对p2p技术有兴趣的同学看一看SkipNet List的广泛应用 从系统底层，到应用层的数据管理 系统层： 内核对象的管理 动态数据块的管理 应用层： 稀疏表格(矩阵) 各种纪录信息 List的一个实现 DDK中单链表的定义 typedef struct _SINGLE_LIST_ENTRY { struct _SINGLE_LIST_ENTRY *Next; } SINGLE_LIST_ENTRY; DDK中双链表的定义 typedef struct _LIST_ENTRY { struct _LIST_ENTRY *Flink; struct _LIST_ENTRY *Blink; } LIST_ENTRY; stack stack: a linear data structure, it can be accessed only at one of its ends for storing and retrieving data. The last entry put in the stack is the first entry removed from the stack. —— LIFO(Last in/first out，后进先出) Stack is like a special container, a stack of trays in a cafeteria: New trays are put on top of the stack The trays are taken off just from the top of the stack, not from the middle or the bottom of the stack Stack: C function calls how to implement function calls in C? C function calls Stack frame or activation record Before entering a function, the caller stores the specific state info into a stack frame, and resume the state after the function finishes. If all stack frames are put into a container, the stack frame retrieved at the time of resuming the caller’s state is the one put recently —— LIFO Stack can be used to implement the function calls The stack frame in C function calls Delimiter Matching in C expression S=t[5]+u/(v*(w+y)) Output pairs (u,v) such that the left delimiter at position u is matched with the right delimiter at v. (3,5) (9,17) (12,16) (a+b))*((c+d) right parenthesis at 4 has no matching left parenthesis (7,11) left parenthesis at 6 has no matching right parenthesis Delimiter Matching scan expression from left to right when a left delimiter is encountered, add its position to the stack when a right delimiter is encountered, remove matching position from stack Example S=t[5]+u/(v*(w+y)) Example S=t[5]+u/(v*(w+y)) Example S=t[5