Notes

STACK USING ARRAY
#include<stdio.h>
#include<conio.h>
#define MAX 5

typedef struct stag
{
int top; int ele[MAX];
} STACK;

void initialize(STACK *sp)
{
sp->top = -1;
}

void push(STACK *sp, int x)
{
if(sp->top == MAX-1) printf("nStack Overflow"); else sp->ele[++sp->top] = x;
}

int pop(STACK *sp)
{ int x; if(sp->top == -1) printf("nStack Underflow"); else x = sp->ele[sp->top--]; return x;
}

int isfull(STACK *sp)
{
if(sp->top == MAX-1) return 1; else return 0;
}



int isempty(STACK *sp)
{
if(sp->top == -1) return 1; else return 0;
}

int main()
{
STACK s;
int x; initialize(&s); push(&s, 70); push(&s, 80);

while(!isempty(&s))
{
x = pop(&s); printf("n The popped element is %d", x);
}
return 0;
}
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SELECTION SORT
#include <stdio.h>
void swap(int *xp, int *yp)
{
int temp = *xp;
*xp = *yp;
*yp = temp;
}

void selectionSort(int arr[], int n)
{
int i, j, min_idx;
for (i = 0; i < n-1; i++)
{ min_idx = i;
for (j = i+1; j < n; j++)
if (arr[j] < arr[min_idx])
min_idx = j;
if(min_idx != i)
swap(&arr[min_idx], &arr[i]);
}
}
void printArray(int arr[], int size)
{
int i;
for (i=0; i < size; i++)
printf("%d ", arr[i]);
printf("n");
}
int main()
{
int arr[] = {64, 25, 12, 22, 11};
int n = sizeof(arr)/sizeof(arr[0]);
selectionSort(arr, n);
printf("Sorted array: n");
printArray(arr, n);
return 0;
}
___________________________________________________________________________________________________________________________________________________________________________
SINGLY LINKED LIST
#include <stdio.h>
#include <stdlib.h>

struct Node
{ int data;
struct Node *next;
};
void push(struct Node** head_ref, int new_data)
{
struct Node* new_node = (struct Node*) malloc(sizeof(struct Node));
new_node->data = new_data;
new_node->next = (*head_ref);
(*head_ref) = new_node;
}
void insertAfter(struct Node* prev_node, int new_data)
{
if (prev_node == NULL)
{
printf("the given previous node cannot be NULL"); return;
}
struct Node* new_node =(struct Node*) malloc(sizeof(struct Node));
new_node->data = new_data;
new_node->next = prev_node->next;
prev_node->next = new_node;
}
void append(struct Node** head_ref, int new_data)
{
/* 1. allocate node */
struct Node* new_node = (struct Node*) malloc(sizeof(struct Node));
struct Node *last = *head_ref;
new_node->data = new_data;
new_node->next = NULL;
if (*head_ref == NULL)
{
*head_ref = new_node;
return;
}
while (last->next != NULL)
last = last->next;
last->next = new_node;
return;
}
void printList(struct Node *node)
{
while (node != NULL)
{
printf(" %d ", node->data);
node = node->next;
}
}
int main()
{
struct Node* head = NULL; append(&head, 6);
push(&head, 7);
push(&head, 1);
append(&head, 4);
insertAfter(head->next, 8);
printf("n Created Linked list is: "); printList(head);
return 0; }
Deletion
#include <stdio.h>
#include <stdlib.h>
struct node {
int data; struct node *next;
}*head;
void createList(int n); void deleteFirstNode();
void displayList();
int main() { int n, choice;
printf("Enter the total number of nodes: "); scanf("%d", &n);
createList(n);
printf("nData in the list n"); displayList();
printf("nPress 1 to delete first node: ");
scanf("%d", &choice); if(choice == 1)
deleteFirstNode();
printf("nData in the list n"); displayList();
return 0; }
void createList(int n)
{
struct node *newNode, *temp;
int data, i;
head = (struct node *)malloc(sizeof(struct node));
if(head == NULL)
{
printf("Unable to allocate memory.");
} else
{
printf("Enter the data of node 1: "); scanf("%d", &data);
head->data = data;
head->next = NULL;
temp = head;
for(i=2; i<=n; i++)
{
newNode = (struct node *)malloc(sizeof(struct node));
if(newNode == NULL)
{
printf("Unable to allocate memory."); break;
}
else
{
printf("Enter the data of node %d: ", i); scanf("%d", &data);
newNode->data = data;
newNode->next = NULL;
temp->next = newNode;
temp = temp->next;
}
}
printf("SINGLY LINKED LIST CREATED SUCCESSFULLYn");
}
}
void deleteFirstNode()
{
struct node *toDelete;
if(head == NULL)
{
printf("List is already empty.");
} else
{
toDelete = head;
head = head->next;
printf("nData deleted = %dn", toDelete->data);
free(toDelete);
printf("SUCCESSFULLY DELETED FIRST NODE FROM LISTn");
}
}
void displayList()
{
struct node *temp;
if(head == NULL)
{
printf("List is empty.");
} else
{ temp = head;
while(temp != NULL)
{
printf("Data = %dn", temp->data); temp = temp->next;
}
}
}