Program for traversing a graph through BFS and DFS

Breadth-first search (BFS) and depth-first search (DFS) are two distinct orders in which to visit the vertices and edges of a graph. BFS radiates out from a root to visit vertices in order of their distance from the root. Thus closer nodes get visited first.

#include<stdio.h>
#define MAX 20
typedef enum boolean{false,true} bool;
int adj[MAX][MAX];
bool visited[MAX];
int n; /* Denotes number of nodes in the graph */
main()
{
int i,v,choice;
create_graph();
while(1)
{
printf("\n");
printf("1. Adjacency matrix\n");
printf("2. Depth First Search using stack\n");
printf("3. Depth First Search through recursion\n");
printf("4. Breadth First Search\n");
printf("5. Adjacent vertices\n");
printf("6. Components\n");
printf("7. Exit\n");
printf("Enter your choice : ");
scanf("%d",&choice);

Implementation of Binary Search Tree

                                 A binary search tree is a tree where each node has a left and right child. Either child, or both children, may be missing. Figure 3-2 illustrates a binary search tree. Assuming k represents the value of a given node, then a binary search tree also has the following property: all children to the left of the node have values smaller than k, and all children to the right of the node have values larger than k. The top of a tree is known as the root, and the exposed nodes at the bottom are known as leaves.                                                                                                                                                                                                                                    

Implementation of Binary Search Tree


# include <stdio.h>
# include <malloc.h>
struct node
{
int info;
struct node *lchild;
struct node *rchild;
}*root;
main()
{
int choice,num;
root=NULL;
clrscr();
while(1)
{
printf("\n");
printf("1.Insert\n");
printf("2.Delete\n");
printf("3.Inorder Traversal\n");
printf("6.Display\n");
printf("7.Quit\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
printf("Enter the number to be inserted : ");
scanf("%d",&num);
insert(num);
break;
case 2:
printf("Enter the number to be deleted : ");
scanf("%d",&num);
del(num);
break;
case 3:
inorder(root);
break;
case 6:
display(root,1);
break;
case 7:
exit();
default:
printf("Wrong choice\n");
}/*End of switch */
}/*End of while */
}/*End of main()*/
find(int item,struct node **par,struct node **loc)
{
struct node *ptr,*ptrsave;
if(root==NULL) /*tree empty*/
{
*loc=NULL;
*par=NULL;
return;
}
if(item==root->info) /*item is at root*/
{
*loc=root;
*par=NULL;
return;
}
/*Initialize ptr and ptrsave*/
if(item<root->info)
ptr=root->lchild;
else
ptr=root->rchild;
ptrsave=root;
while(ptr!=NULL)
{
if(item==ptr->info)
{ *loc=ptr;
*par=ptrsave;
return;
}
ptrsave=ptr;
if(item<ptr->info)
ptr=ptr->lchild;
else
ptr=ptr->rchild;
}/*End of while */
*loc=NULL; /*item not found*/
*par=ptrsave;
}/*End of find()*/
insert(int item)
{ struct node *tmp,*parent,*location;
find(item,&parent,&location);
if(location!=NULL)
{
printf("Item already present");
return;
}
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=item;
tmp->lchild=NULL;
tmp->rchild=NULL;
if(parent==NULL)
root=tmp;
else
if(item<parent->info)
parent->lchild=tmp;
else
parent->rchild=tmp;
}/*End of insert()*/
del(int item)
{
struct node *parent,*location;
if(root==NULL)
{
printf("Tree empty");
return;
}
find(item,&parent,&location);
if(location==NULL)
{
printf("Item not present in tree");
return;
}
if(location->lchild==NULL && location->rchild==NULL)
case_a(parent,location);
if(location->lchild!=NULL && location->rchild==NULL)
case_b(parent,location);
if(location->lchild==NULL && location->rchild!=NULL)
case_b(parent,location);
if(location->lchild!=NULL && location->rchild!=NULL)
case_c(parent,location);
free(location);
}/*End of del()*/
case_a(struct node *par,struct node *loc )
{
if(par==NULL) /*item to be deleted is root node*/
root=NULL;
else
if(loc==par->lchild)
par->lchild=NULL;
else
par->rchild=NULL;
}/*End of case_a()*/
case_b(struct node *par,struct node *loc)
{
struct node *child;
/*Initialize child*/
if(loc->lchild!=NULL) /*item to be deleted has lchild */
child=loc->lchild;
else /*item to be deleted has rchild */
child=loc->rchild;
if(par==NULL ) /*Item to be deleted is root node*/
root=child;
else
if( loc==par->lchild) /*item is lchild of its parent*/
par->lchild=child;
else /*item is rchild of its parent*/
par->rchild=child;
}/*End of case_b()*/
case_c(struct node *par,struct node *loc)
{
struct node *ptr,*ptrsave,*suc,*parsuc;
/*Find inorder successor and its parent*/
ptrsave=loc;
ptr=loc->rchild;
while(ptr->lchild!=NULL)
{
ptrsave=ptr;
ptr=ptr->lchild;
}
suc=ptr;
parsuc=ptrsave;
if(suc->lchild==NULL && suc->rchild==NULL)
case_a(parsuc,suc);
else
case_b(parsuc,suc);
if(par==NULL) /*if item to be deleted is root node */
root=suc;
else
if(loc==par->lchild)
par->lchild=suc;
else
par->rchild=suc;
suc->lchild=loc->lchild;
suc->rchild=loc->rchild;
}/*End of case_c()*/
inorder(struct node *ptr)
{
if(root==NULL)
{
printf("Tree is empty");
return;
}
if(ptr!=NULL)
{
inorder(ptr->lchild);
printf("%d ",ptr->info);
inorder(ptr->rchild);
}
}/*End of inorder()*/
display(struct node *ptr,int level)
{
int i;
if ( ptr!=NULL )
{
display(ptr->rchild, level+1);
printf("\n");
for (i = 0; i < level; i++)
printf(" ");
printf("%d", ptr->info);
display(ptr->lchild, level+1);
}/*End of if*/
}/*End of display()*/

explanation of DDA algorithm

DDA : Digital Differential Analyzer

The dda is scan-conversion line algorithm based  on calculating dx and dy.

DDA algorithm    

DDA(int xa, int ya,int xb,int yb)
{
x = xa
y = ya
dx = xb - xa
dy = yb - ya

Binary sorting in C langaugae

The basic algorithm is this:

1. Select an arbitrary element and add it to our sorted list, S.
2. Select another arbirtrary element, x, and, using binary search, try to find x in S.
3. Place x in S according to the results of the binary search.
4. Repeat steps 2 and 3 until there are no more elements to select.

C program for binary search: This code implements binary search in c language. It can only be used for sorted arrays, but it's fast as compared to linear search. If you wish to use binary search on an array which is not sorted then you must sort it using some sorting technique say merge sort and then use binary search algorithm to find the desired element in the list. If the element to be searched is found then its position is printed.

Infix program in C program data structure

Infix notation is the common arithmetic and logical formula notation, in which operators are written infix-style between the operands they act on (e.g. 2 + 2). It is not as simple to parse by computers as prefix notation  but many programming languages use it due to its familiarity.

#include<stdio.h>
#include<conio.h>
#include<string.h>
#define MAX 20
char stack[MAX];
int top=-1;
char pop();
void push(char item);
int prcd(char symbol)
{