有序单链表的去重
1 #include<stdio.h>
2 #include<stdlib.h>
3
4 typedef int Elemtype;
5 typedef struct Node
6 {
7 Elemtype data;
8 struct Node *next;
9 }Node, *LinkedList;
10
11 //单链表的初始化
12 LinkedList LinkedListInit()
13 {
14 Node *L;
15 L = (Node*)malloc(sizeof(Node));
16 if (L == NULL)
17 {
18 printf("申请内存空间失败\n");
19 }
20 L->next = NULL;
21 return L;
22 }
23
24 //单链表的创建一：头插法建立单链表
25 LinkedList LinkedListCreatH()
26 {
27 Node *L;
28 L = (Node *)malloc(sizeof(Node));
29 L->next = NULL;
30
31 Elemtype x;
32 while (scanf("%d", &x) != EOF)
33 {
34 Node *p;
35 p = (Node *)malloc(sizeof(Node));
36 p->data = x;
37 p->next = L->next;
38 L->next = p;
39 }
40 return L;
41 }
42
43 //单链表的创建二：尾插法建立单链表
44 LinkedList LinkedListCreatT()
45 {
46 Node *L;
47 L = (Node *)malloc(sizeof(Node));
48 L->next = NULL;
49 Node *r;
50 r = L;
51 Elemtype x;
52 while (scanf("%d", &x) != EOF)
53 {
54 Node *p;
55 p = (Node *)malloc(sizeof(Node));
56 p->data = x;
57 //p->next = NULL;
58 r->next = p;
59 r = p;
60 }
61 r->next = NULL;
62 return L;
63 }
64
65 //单链表的插入，在链表的第i个位置插入x的元素
66 //要在第i个位置插入，就得先找到第(i-1)个位置，插在它后面
67 LinkedList LinkedListInsert(LinkedList L, int i, Elemtype x)
68 {
69 Node *pre;
70 pre = L;
71 int tempi = 0;
72 for (tempi = 1; tempi < i; tempi++)
73 pre = pre->next;
74 Node *p;
75 p = (Node *)malloc(sizeof(Node));
76 p->data = x;
77 p->next = pre->next;
78 pre->next = p;
79 return L;
80 }
81
82 //单链表的删除，在链表中删除第一个值为x的元素
83 LinkedList LinkedListDelete(LinkedList L, Elemtype x)
84 {
85 Node *pre, *p;
86 p = L->next;
87 while (p->data != x)
88 {
89 pre = p;
90 p = p->next;
91 }
92 pre->next = p->next;
93 free(p);
94 return L;
95 }
96
97 //单链表的反转
98 LinkedList LinkedListReverse(LinkedList L)
99 {
100
101 Node *rhead = NULL;
102 Node *prev = NULL;
103 Node *p = L->next;//如果原链表的头是一个结点，结点的内容为任意值，p要指向头的下一个结点才是链表的第一个值
104 //Node *p = L;//如果原链表的头是一个指针，p直接等于Lj就可以了，L指的就是链表的第一个值
105 Node *pnext = NULL;
106 while (p != NULL)
107 {
108 pnext = p->next;
109 if (pnext == NULL)
110 rhead = p;
111 p->next = prev;
112 prev = p;
113 p = pnext;
114 }
115 free(L);
116 return rhead;
117 }
118
119 //有序单链表的去重一
120 //输入1->2->2->3,输出1->2->3
121 LinkedList DeleteDuplicates_1(LinkedList L)
122 {
123 if (L == NULL || L->next == NULL||L->next->next==NULL)
124 return L;
125 //if (L == NULL || L->next == NULL)//如果不存在哨兵结点
126 // return L;
127 Node *pre;
128 Node *p;
129 Node *pnext;
130 pre = L->next;//因为第一个结点L是哨兵结点,所以指向L的下一个结点
131 p = L->next->next;
132 //pre = L;//如果不存在哨兵结点
133 //p = L->next;
134 while (p != NULL)
135 {
136 pnext = p->next;
137 if (pre->data == p->data)
138 {
139 pre->next = pnext;
140 free(p);
141 }
142 else
143 pre = p;
144 p = pnext;
145 }
146 return L;
147 }
148
149 //有序单链表的去重二
150 //输入1->2->2->3,输出1->3
151 //输入1->1->2->3,输出2->3
152 LinkedList DeleteDuplicates_2(LinkedList L)//如果存在哨兵结点
153 {
154 if (L == NULL || L->next == NULL || L->next->next == NULL)
155 return L;
156 Node *prere;
157 Node *pre;
158 Node *p;
159 Node *pnext;
160 int flag = 0;
161 prere = L;
162 pre = L->next;//因为第一个结点是哨兵结点
163 p = L->next->next;
164 //pre = L;//如果不存在哨兵结点
165 //p = L->next;
166 while (p != NULL)
167 {
168 pnext = p->next;
169 if (pre->data == p->data)
170 {
171 pre->next = pnext;
172 free(p);
173 flag = 1;
174 }
175 else
176 {
177 if (flag == 1)
178 {
179 prere->next = p;
180 free(pre);
181 pre = p;
182 flag = 0;
183 }
184 else
185 {
186 prere = pre;
187 pre = p;
188 }
189 }
190 p = pnext;
191 }
192 return L;
193 }
194
195 LinkedList DeleteDuplicates_3(LinkedList L)//如果不存在哨兵结点
196 {
197 if (L == NULL || L->next == NULL)
198 return L;
199 Node *prere;
200 Node *pre;
201 Node *p;
202 Node *pnext;
203 int flag = 0;
204 pre = L;//如果不存在哨兵结点
205 prere = L;
206 prere--;
207 p = L->next;
208 while (p != NULL)
209 {
210 pnext = p->next;
211 if (pre->data == p->data)
212 {
213 pre->next = pnext;
214 free(p);
215 flag = 1;
216 }
217 else
218 {
219 if (flag == 1)
220 {
221 if (pre == L)
222 {
223 L = p;
224 free(pre);
225 pre = p;
226 prere = p;
227 prere--;
228 }
229 else
230 {
231 prere->next = p;
232 free(pre);
233 pre = p;
234 }
235 flag = 0;
236 }
237 else
238 {
239 prere = pre;
240 pre = p;
241 }
242 }
243 p = pnext;
244 }
245 if (flag == 1)
246 {
247 if (pre == L)
248 {
249 L = p;
250 free(pre);
251 pre = p;
252 prere = p;
253 prere--;
254 }
255 else
256 {
257 prere->next = p;
258 free(pre);
259 pre = p;
260 }
261 flag = 0;
262 }
263 return L;
264 }
265
266 int main()
267 {
268 LinkedList list, start;
269
270 //单链表的创建一：头插法建立单链表
271 printf("请输入单链表的数据：");
272 list = LinkedListCreatH();
273 for (start = list->next; start != NULL; start = start->next)
274 printf("%d", start->data);
275 printf("\n");
276
277 //单链表的创建二：尾插法建立单链表
278 printf("请输入单链表的数据：");
279 list = LinkedListCreatT();
280 for (start = list->next; start != NULL; start = start->next)
281 printf("%d", start->data);
282 printf("\n");
283
284 //单链表的插入，在链表的第i个位置插入x的元素
285 int i, x;
286 printf("请输入插入数据的位置：");
287 scanf("%d", &i);
288 printf("请输入插入数据的值：");
289 scanf("%d", &x);
290 LinkedListInsert(list, i, x);
291 for (start = list->next; start != NULL; start = start->next)
292 printf("%d", start->data);
293 printf("\n");
294
295 //单链表的删除，在链表中删除第一个值为x的元素
296 printf("请输入要删除的元素的值：");
297 scanf("%d", &x);
298 LinkedListDelete(list, x);
299 for (start = list->next; start != NULL; start = start->next)
300 printf("%d", start->data);
301 printf("\n");
302
303 //单链表的反转
304 LinkedList rhead;
305 rhead = LinkedListReverse(list);
306 for (start = rhead; start != NULL; start = start->next)
307 printf("%d", start->data);
308 printf("\n");
309
310
311 /*************************************************************/
312 //单链表的创建二：尾插法建立单链表
313 printf("请输入单链表的数据：");
314 list = LinkedListCreatT();
315 for (start = list->next; start != NULL; start = start->next)
316 printf("%d", start->data);
317 printf("\n");
318
319 //有序单链表的去重一
320 //输入1->2->2->3,输出1->2->3
321 DeleteDuplicates_1(list);
322 for (start = list->next; start != NULL; start = start->next)
323 printf("%d", start->data);
324 printf("\n");
325
326
327 //有序单链表的去重二
328 //输入1->2->2->3,输出1->3
329 //输入1->1->2->3,输出2->3
330 DeleteDuplicates_2(list);//如果存在哨兵结点
331 for (start = list->next; start != NULL; start = start->next)
332 printf("%d", start->data);
333 printf("\n");
334
335 rhead=DeleteDuplicates_3(list);//如果不存在哨兵结点
336 for (start = rhead; start != NULL; start = start->next)
337 printf("%d", start->data);
338 printf("\n");
339
340 system("pause");
341 return 0;
342 }
343 //注意：结束输入的时候连续输入三个ctrl+z
