ListSet_有序表搜索

来源：互联网发布：javascript面试编辑：程序博客网时间：2024/06/05 15:10

一个有序表可以看成是一个已按关键字排序的有序集.

表的最后添增设了一个被称作哨兵的元素, 关键字为INF. 若表长为n, 需要在l[n]位置存放哨兵元素. 增加哨兵元素以后, 在for循环中不再

需要通过下标来判定是否已经查完整个表. 当表中l[i]的关键字值大于等于指定元素x的关键字时, for循环结束.

搜索失败的平均搜索长度: n / 2 + 2.

实现代码:

#include "iostream"#include "cstdio"#include "cstring"#include "algorithm"#include "assert.h"using namespace std;const int MAXN = 9999;enum ResultCode{    Underflow, Overflow, Success, Duplicate, NotPresent};template <class T>class DynamicSet{public:virtual ResultCode Search(T &x) const = 0; // 表中搜索与x关键字相同的元素, 若存在则赋值给x并且返回Success, 否则返回NotPresentvirtual ResultCode Insert(T &x) = 0; // 表中搜索与x关键字相同的元素, 若存在该元素, 赋值给x返回Duplicate, 若表已满返回Overflow, 若表未满返回Successvirtual ResultCode Remove(T &x) = 0; // 表中搜索与x关键字相同的元素, 若存在该元素, 赋值给x返回Success, 否则返回NotPresentvirtual bool IsEmpty() const = 0; // 集合为空返回truevirtual bool IsFull() const = 0; // 集合为满返回true/* data */};template <class T>class ListSet: public DynamicSet<T>{public:ListSet( int mSize );~ListSet() { delete []l; }bool IsEmpty() const { return n == 0; }bool IsFull() const { return n == maxSize; }ResultCode Search(T &x) const;ResultCode Insert(T &x);ResultCode Remove(T &x);void Print();private:T *l;int maxSize, n;/* data */};template <class T>void ListSet<T>::Print(){for(int i = 0; i < n; ++i)cout << l[i] << "\t";cout << endl;}template <class T>ListSet<T>::ListSet(int mSize){maxSize = mSize;l = new T[maxSize];n = 0;}template <class T>ResultCode ListSet<T>::Insert(T &x){assert(!IsFull());l[n++] = x;l[n] = MAXN;return Success;}template <class T>ResultCode ListSet<T>::Remove(T &x){}template <class T>ResultCode ListSet<T>::Search(T &x) const{for(int i = 0; l[i] <= x; ++i)if(l[i] == x) {x = l[i];return Success;}return NotPresent;}int main(int argc, char const *argv[]){ListSet<int> ls(20);int x = 11; ls.Insert(x);x = 22; ls.Insert(x);x = 33; ls.Insert(x);x = 44; ls.Insert(x);x = 88; ls.Insert(x);x = 100; ls.Insert(x);ls.Print();x = 88;if(ls.Search(x) == Success) cout << "Found " << x << endl;else cout << "Not Found " << x << endl;return 0;}

1 0