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5.c(file created)

@@ -0,0 +1,257 @@
1 + /*
2 + * Ex. No. 5: IMPLEMENTATION OF LINKED LIST
3 + * Student Record Management System using a singly linked list
4 + * Supports: INSERT (beginning/end/position), DELETE (beginning/end/position),
5 + * SEARCH, DISPLAY
6 + */
7 + #include <stdio.h>
8 + #include <stdlib.h>
9 + #include <string.h>
10 +
11 + #define NAME_LEN 50
12 +
13 + struct Node {
14 + int regNo;
15 + char name[NAME_LEN];
16 + struct Node *next;
17 + };
18 +
19 + struct Node *head = NULL;
20 +
21 + /* Count nodes in list */
22 + int countNodes(void) {
23 + int count = 0;
24 + struct Node *cur = head;
25 + while (cur != NULL) {
26 + count++;
27 + cur = cur->next;
28 + }
29 + return count;
30 + }
31 +
32 + /* Allocate and fill a new node */
33 + struct Node *makeNode(int regNo, const char *name) {
34 + struct Node *node = (struct Node *)malloc(sizeof(struct Node));
35 + node->regNo = regNo;
36 + strncpy(node->name, name, NAME_LEN - 1);
37 + node->name[NAME_LEN - 1] = '\0';
38 + node->next = NULL;
39 + return node;
40 + }
41 +
42 + /* i) Insert at Beginning */
43 + void insertBeginning(int regNo, const char *name) {
44 + struct Node *node = makeNode(regNo, name);
45 + node->next = head;
46 + head = node;
47 + printf("Inserted at beginning.\n");
48 + }
49 +
50 + /* ii) Insert at End */
51 + void insertEnd(int regNo, const char *name) {
52 + struct Node *node = makeNode(regNo, name);
53 + if (head == NULL) {
54 + head = node;
55 + } else {
56 + struct Node *cur = head;
57 + while (cur->next != NULL)
58 + cur = cur->next;
59 + cur->next = node;
60 + }
61 + printf("Inserted at end.\n");
62 + }
63 +
64 + /* iii) Insert at a Given Position (1-based) */
65 + void insertAtPosition(int pos, int regNo, const char *name) {
66 + int size = countNodes();
67 + if (pos < 1 || pos > size + 1) {
68 + printf("Invalid position.\n");
69 + return;
70 + }
71 + if (pos == 1) {
72 + insertBeginning(regNo, name);
73 + return;
74 + }
75 + struct Node *prev = head;
76 + for (int i = 1; i < pos - 1; i++)
77 + prev = prev->next;
78 + struct Node *node = makeNode(regNo, name);
79 + node->next = prev->next;
80 + prev->next = node;
81 + printf("Inserted at position %d.\n", pos);
82 + }
83 +
84 + /* iv) Delete from Beginning */
85 + void deleteBeginning(void) {
86 + if (head == NULL) {
87 + printf("List is empty.\n");
88 + return;
89 + }
90 + struct Node *doomed = head;
91 + head = head->next;
92 + free(doomed);
93 + printf("Deleted from beginning.\n");
94 + }
95 +
96 + /* v) Delete from End */
97 + void deleteEnd(void) {
98 + if (head == NULL) {
99 + printf("List is empty.\n");
100 + return;
101 + }
102 + if (head->next == NULL) {
103 + free(head);
104 + head = NULL;
105 + printf("Deleted from end.\n");
106 + return;
107 + }
108 + struct Node *cur = head;
109 + while (cur->next->next != NULL)
110 + cur = cur->next;
111 + free(cur->next);
112 + cur->next = NULL;
113 + printf("Deleted from end.\n");
114 + }
115 +
116 + /* vi) Delete from a Given Position (1-based) */
117 + void deleteAtPosition(int pos) {
118 + int size = countNodes();
119 + if (size == 0) {
120 + printf("List is empty.\n");
121 + return;
122 + }
123 + if (pos < 1 || pos > size) {
124 + printf("Invalid position.\n");
125 + return;
126 + }
127 + if (pos == 1) {
128 + deleteBeginning();
129 + return;
130 + }
131 + struct Node *prev = head;
132 + for (int i = 1; i < pos - 1; i++)
133 + prev = prev->next;
134 + struct Node *doomed = prev->next;
135 + prev->next = doomed->next;
136 + free(doomed);
137 + printf("Deleted position %d.\n", pos);
138 + }
139 +
140 + /* vii) Search by register number */
141 + void search(int regNo) {
142 + struct Node *cur = head;
143 + int pos = 1;
144 + while (cur != NULL) {
145 + if (cur->regNo == regNo) {
146 + printf("Found: RegNo=%d, Name=%s, Position=%d\n", cur->regNo, cur->name, pos);
147 + return;
148 + }
149 + cur = cur->next;
150 + pos++;
151 + }
152 + printf("Register number %d not found.\n", regNo);
153 + }
154 +
155 + /* viii) Display all students */
156 + void display(void) {
157 + if (head == NULL) {
158 + printf("List is empty.\n");
159 + return;
160 + }
161 + struct Node *cur = head;
162 + int pos = 1;
163 + printf("--- Student Records ---\n");
164 + while (cur != NULL) {
165 + printf("%d) RegNo=%d, Name=%s\n", pos, cur->regNo, cur->name);
166 + cur = cur->next;
167 + pos++;
168 + }
169 + }
170 +
171 + /* Free all remaining nodes before exit */
172 + void freeList(void) {
173 + struct Node *cur = head;
174 + while (cur != NULL) {
175 + struct Node *next = cur->next;
176 + free(cur);
177 + cur = next;
178 + }
179 + head = NULL;
180 + }
181 +
182 + void readName(char *name) {
183 + scanf(" %49[^\n]", name);
184 + }
185 +
186 + int main(void) {
187 + int choice, regNo, pos;
188 + char name[NAME_LEN];
189 +
190 + do {
191 + printf("\n===== Student Record Management System =====\n");
192 + printf("1. Insert at Beginning\n");
193 + printf("2. Insert at End\n");
194 + printf("3. Insert at a Given Position\n");
195 + printf("4. Delete from Beginning\n");
196 + printf("5. Delete from End\n");
197 + printf("6. Delete from a Given Position\n");
198 + printf("7. Search\n");
199 + printf("8. Display\n");
200 + printf("9. Exit\n");
201 + printf("Enter your choice: ");
202 + scanf("%d", &choice);
203 +
204 + switch (choice) {
205 + case 1:
206 + printf("Enter register number: ");
207 + scanf("%d", &regNo);
208 + printf("Enter name: ");
209 + readName(name);
210 + insertBeginning(regNo, name);
211 + break;
212 + case 2:
213 + printf("Enter register number: ");
214 + scanf("%d", &regNo);
215 + printf("Enter name: ");
216 + readName(name);
217 + insertEnd(regNo, name);
218 + break;
219 + case 3:
220 + printf("Enter position: ");
221 + scanf("%d", &pos);
222 + printf("Enter register number: ");
223 + scanf("%d", &regNo);
224 + printf("Enter name: ");
225 + readName(name);
226 + insertAtPosition(pos, regNo, name);
227 + break;
228 + case 4:
229 + deleteBeginning();
230 + break;
231 + case 5:
232 + deleteEnd();
233 + break;
234 + case 6:
235 + printf("Enter position: ");
236 + scanf("%d", &pos);
237 + deleteAtPosition(pos);
238 + break;
239 + case 7:
240 + printf("Enter register number to search: ");
241 + scanf("%d", &regNo);
242 + search(regNo);
243 + break;
244 + case 8:
245 + display();
246 + break;
247 + case 9:
248 + printf("Exiting...\n");
249 + break;
250 + default:
251 + printf("Invalid choice.\n");
252 + }
253 + } while (choice != 9);
254 +
255 + freeList();
256 + return 0;
257 + }
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