In this program, we are going to share Java program to implement singly linked list with the output. If you are a Java beginner and want to start learning the Java programming, then keep your close attention in this tutorial as I am going to share how to write a Java program to implement singly linked list.
Copy the below Java program and execute it with the help of Javac compiler. At the end of this program, We have shared the output of this program.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 | import java.util.Scanner; class Node { protected int data; protected Node link; public Node() { link = null; data = 0; } public Node(int d,Node n) { data = d; link = n; } public void setLink(Node n) { link = n; } public void setData(int d) { data = d; } public Node getLink() { return link; } public int getData() { return data; } } class linkedList { protected Node start; protected Node end ; public int size ; public linkedList() { start = null; end = null; size = 0; } public boolean isEmpty() { return start == null; } public int getSize() { return size; } public void insertAtStart(int val) { Node nptr = new Node(val, null); size++ ; if(start == null) { start = nptr; end = start; } else { nptr.setLink(start); start = nptr; } } public void insertAtEnd(int val) { Node nptr = new Node(val,null); size++ ; if(start == null) { start = nptr; end = start; } else { end.setLink(nptr); end = nptr; } } public void insertAtPos(int val , int pos) { Node nptr = new Node(val, null); Node ptr = start; pos = pos - 1 ; for (int i = 1; i < size; i++) { if (i == pos) { Node tmp = ptr.getLink() ; ptr.setLink(nptr); nptr.setLink(tmp); break; } ptr = ptr.getLink(); } size++ ; } public void deleteAtPos(int pos) { if (pos == 1) { start = start.getLink(); size--; return ; } if (pos == size) { Node s = start; Node t = start; while (s != end) { t = s; s = s.getLink(); } end = t; end.setLink(null); size --; return; } Node ptr = start; pos = pos - 1 ; for (int i = 1; i < size - 1; i++) { if (i == pos) { Node tmp = ptr.getLink(); tmp = tmp.getLink(); ptr.setLink(tmp); break; } ptr = ptr.getLink(); } size-- ; } public void display() { System.out.print("\nSingly Linked List = "); if (size == 0) { System.out.print("empty\n"); return; } if (start.getLink() == null) { System.out.println(start.getData() ); return; } Node ptr = start; System.out.print(start.getData()+ "->"); ptr = start.getLink(); while (ptr.getLink() != null) { System.out.print(ptr.getData()+ "->"); ptr = ptr.getLink(); } System.out.print(ptr.getData()+ "\n"); } } public class SinglyLinkedList { public static void main(String[] args) { Scanner scan = new Scanner(System.in); linkedList list = new linkedList(); System.out.println("Singly Linked List Test\n"); char ch; do { System.out.println("\nSingly Linked List Operations\n"); System.out.println("1. insert at begining"); System.out.println("2. insert at end"); System.out.println("3. insert at position"); System.out.println("4. delete at position"); System.out.println("5. check empty"); System.out.println("6. get size"); int choice = scan.nextInt(); switch (choice) { case 1 : System.out.println("Enter integer element to insert"); list.insertAtStart( scan.nextInt() ); break; case 2 : System.out.println("Enter integer element to insert"); list.insertAtEnd( scan.nextInt() ); break; case 3 : System.out.println("Enter integer element to insert"); int num = scan.nextInt() ; System.out.println("Enter position"); int pos = scan.nextInt() ; if (pos <= 1 || pos > list.getSize() ) System.out.println("Invalid position\n"); else list.insertAtPos(num, pos); break; case 4 : System.out.println("Enter position"); int p = scan.nextInt() ; if (p < 1 || p > list.getSize() ) System.out.println("Invalid position\n"); else list.deleteAtPos(p); break; case 5 : System.out.println("Empty status = "+ list.isEmpty()); break; case 6 : System.out.println("Size = "+ list.getSize() +" \n"); break; default : System.out.println("Wrong Entry \n "); break; } list.display(); System.out.println("\nDo you want to continue (Type y or n) \n"); ch = scan.next().charAt(0); } while (ch == 'Y'|| ch == 'y'); } } |
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