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c++模板实现快速排序算法

freejohn — Fri, 13 Jul 2012 07:50:00 GMT

快速排序的思想：以某一个元素key作为基准轴，将原序列划分成左右两部分，左边部分都不大于key，右边部分都不小于key，然后进行上行和下行遍历，下行遍历的时候找到比key小的，然后交换，上行遍历的时候找到比key大的然后交换，一直到上行下行遍历相遇为止，然后此时的位置就是key最终所在的位置，然后分别对左右部分的子序列进行相同的操作，递归进行，最终实现对数组的排序。
1 /*
2  * QuickSort.cpp
3  * author : freejohn
4  * time : 2012-07-13
5  */
6
7 #include <cstdio>
8 #include <cstring>
9 #include <iostream>
10 #include <iterator>
11 #include <string>
12 #include <cstdlib>
13 #include <cassert>
14 using namespace std;
15
16 template <typename T>
17 int partion(T* array, int l, int r)
18 {
19     int low, high;
20     low = l;
21     high = r;
22     T key = array[low];
23     while(high != low)
24     {
25         while(low < high && array[high] >= key) --high;
26         if(low < high)
27         {
28             array[low] = array[high];
29             ++low;
30         }
31         while(low < high && array[low] <= key) ++low;
32         if(low < high)
33         {
34             array[high] = array[low];
35             --high;
36         }
37     }
38     array[high] = key;
39     return high;
40 }
41
42 template <typename T>
43 void QuickSort(T* array, int l, int r)
44 {
45     if(l >= r)
46         return ;
47     int index = partion(array, l, r);
48     //cout << index << endl;
49     QuickSort(array, l, index-1);
50     QuickSort(array, index+1, r);
51 }
52
53 //test
54 int a[10005];
55 int main()
56 {
57     /*int a[10] = {3, 2, 1, 6, 5, 4, 0, 7, 9, 8};
58     QuickSort(a, 0, 9);
59     for(int i=0;i<10;++i)
60       cout << a[i] << " ";
61     cout << endl;*/
62     int n;
63     while(cin>>n)
64     {
65         for(int i=0;i<n;++i)
66             cin >> a[i];
67         QuickSort(a, 0, n-1);
68         cout << a[n/2] << endl;
69     }
70     return 0;
71 }
72

freejohn 2012-07-13 15:50 发表评论

C++模板实现单循环链表

freejohn — Fri, 13 Jul 2012 07:02:00 GMT

C++模板实现单循环链表的各种操作

  1 /*
  2  * LoopLink.cpp
  3  * author : freejohn
  4  * time : 2012-07-12 night
  5  */
  6
  7 #include <cstdio>
  8 #include <cstring>
  9 #include <iostream>
10 #include <iterator>
11 #include <string>
12 #include <cstdlib>
13 #include <cassert>
14 using namespace std;
15
16 template <class T> class CLinkList;
17
18 //定义节点
19 template <class T>
20 class CLNode
21 {
22     friend class CLinkList<T>;
23 public:
24     T data;
25     CLNode<T>* next;
26 };
27
28 template <class T>
29 class CLinkList
30 {
31 public:
32     CLinkList();
33     CLinkList(const CLinkList& );
34     ~CLinkList();
35
36 public:
37     bool Insert(int pos, T e);
38     CLNode<T>* find(int pos);
39     int GetSize();
40     bool Delete(int pos, T& e);
41 private:
42     CLNode<T>* first;
43 };
44
45 template <class T>
46 CLinkList<T>::CLinkList()
47 {
48     first = new CLNode<T>;
49     assert(first!=NULL);
50     first->data = NULL;
51     first->next = first;
52 }
53
54 template <class T>
55 CLinkList<T>::CLinkList(const CLinkList& myList)
56 {
57     CLNode<T>* q = myList.first->next;
58     CLNode<T>* pb = new CLNode<T>;
59     first = pb;
60     while(q != myList.first)
61     {
62         CLNode<T>* p = new CLNode<T>;
63         p->data = q->data;
64         p->next = first;
65         pb->next = p;
66         pb = p;
67         q = q->next;
68     }
69 }
70
71 template <class T>
72 CLinkList<T>::~CLinkList()
73 {
74     CLNode<T>* p = first->next;
75     while(p!=first)
76     {
77         CLNode<T>* q = p;
78         p = p->next;
79         delete q;
80     }
81     delete first;
82 }
83
84 template <class T>
85 bool CLinkList<T>::Insert(int pos, T e)
86 {
87     CLNode<T>* p = find(pos-1);
88     if(p == NULL)
89         return false;
90     CLNode<T>* q = new CLNode<T>;
91     q->data = e;
92     q->next = p->next;
93     p->next = q;
94     return true;
95 }
96
97 template <class T>
98 CLNode<T>* CLinkList<T>::find(int pos)
99 {
100     if(pos<0) return NULL;
101     if(pos==0) return first;
102     int cnt=0;
103     CLNode<T>* p = first->next;
104     while(p!=first&&cnt<pos-1)
105     {
106         ++cnt;
107         p = p->next;
108     }
109     if(cnt<pos-1) return NULL;
110     return p;
111 }
112
113 template <class T>
114 int CLinkList<T>::GetSize()
115 {
116     CLNode<T>* p = first->next;
117     int cnt=0;
118     while(p!=first)
119     {
120         ++cnt;
121         p = p->next;
122     }
123     return cnt;
124 }
125
126 template <class T>
127 bool CLinkList<T>::Delete(int pos, T&e)
128 {
129     CLNode<T>* p = find(pos-1);
130     if(p == NULL)
131         return false;
132     CLNode<T>* q = p->next;
133     p->next = q->next;
134     e = q->data;
135     return true;
136 }
137 //test
138 int main()
139 {
140     int x = NULL;
141     CLinkList<int> testList;
142     cout << testList.Insert(1,4) << endl;
143     cout << testList.Insert(2,5) << endl;
144     cout << testList.Insert(2,5) << endl;
145     cout << testList.GetSize() << endl;
146     cout << testList.find(2)->data << endl;
147     cout << testList.Delete(1, x) << endl;
148     cout << x << endl;
149 }
150
151

freejohn 2012-07-13 15:02 发表评论

C++模板实现单链表

freejohn — Fri, 13 Jul 2012 06:59:00 GMT

摘要: 利用C++模板实现单链表的各种操作Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> 1 /* 2 * SingleLink.cpp 3 ... 阅读全文

freejohn 2012-07-13 14:59 发表评论