Searching Method in C - Linear Search/Binary Search/Depth first search

Searching Method in C - Linear Search/Binary Search/Depth first search
==========================================================

Linear Search
=============

#include <stdio.h>
#include <conio.h>
void main ()
{
int array[20], n, sea_no, i, j;
int create (int []);
int linear_search (int [], int, int);
clrscr ();
n = create (array);
printf("\nEnter the number you want to search: ");
scanf ("%d",&sea_no);
clrscr ();
i = linear_search (array, n, sea_no);
if (i == 0)
printf ("\nSearch value does not exist");
else
printf("\nThe search value is at location %d\n",i);
printf("\nThe array is as follows:\n");
for (j = 0 ; j < n ; j++)
printf("%d ",array[j]);
getch ();
}

int create (int a[20])
{
int n, i;
printf("\nEnter how many numbers you want to enter(Enter less than 20): ");
scanf("%d",&n);
printf("\nEnter the numbers:\n");
for (i = 0 ; i < n ; i++)
scanf("%d",&a[i]);
return (n);
}

int linear_search (int a[], int n, int s)
{
int i;
for (i = 0 ; i < n ; i++)
{
if(s == a[i])
{
printf("\nSEARCH VALUE FOUND\n");
return (i+1);
}
}
return (0);
}


Binary Search
==============

#include <stdio.h>
#include <conio.h>

void main ()
{
int a[20], n, sea_no;
int create (int []);
void binary_search (int [], int, int);
clrscr ();
n = create(a);
printf("\nEnter the number you want to search: ");
scanf("%d",&sea_no);
clrscr ();
binary_search (a,n,sea_no);
getch ();
}

int create (int a[20])
{
int n, i;
do
{
printf("\nEnter how many numbers you want to enter(Enter less than 20): ");
scanf("%d",&n);
} while (n > 20);
if (n == 0)
{
printf("Invalid number, Press any key to exit\n");
getch ();
printf("Termenating the Program.....");
delay (1500);
exit (1);
}
printf("\nEnter the numbers in ascending order:\n");
for (i = 0 ; i < n ; i++)
scanf("%d",&a[i]);
return (n);
}

void binary_search (int a[], int n, int s)
{
int lb = 0,ub = n-1,mid, flag = 1, i;
while (lb <= ub)
{
mid = (lb + ub)/2;
if (s < a[mid])
ub = mid - 1;
if (s > a[mid])
lb = mid + 1;
if (s == a[mid])
{
flag = 0;
printf("\nSEARCH FOUND\n");
printf("\nThe number you want to search is at location %d\n",mid + 1);
printf("\nThe elements are as follows:\n");
for (i = 0 ; i < n ; i++)
printf("%d ",a[i]);
break;
}
}
if (flag == 1)
{
printf("\nSearch element does not found");
}
}


Depth first search
===============


#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<malloc.h>

#define size 20
#define T 1
#define F 0

struct Edge
{
int terminal;
struct Edge *next;
};
struct Vertex
{
int visit;
int vertexno;
char info;
int path_length;
struct Edge *edgeptr;
};
void table(int vertexno,int matrix[size][size],struct Vertex vert[size]);
struct Edge *insert_vertex(int vertexno,struct Edge * first);
void dfs(int index,int *dist,struct Vertex vert[size]);
void output(int number,int a[size][size]);
void input(int number,int a[size][size]);

struct Edge *insert_vertex(int vertexno, struct Edge *first)
{
struct Edge * newl,*current;
newl = (struct Edge *)malloc(sizeof(struct Edge));
newl->terminal = vertexno;
newl->next = NULL;
if(first)
return(newl);
for(current = first; current->next;current=current->next)
current->next = newl;
return(first);
}
void table(int vertexno,int matrix[size][size],struct Vertex vert[size])
{
int i,j;
for(i=0;i<vertexno;i++)
{
vert[i].visit = F;
vert[i].vertexno = i+1;
vert[i].info = 'A' + i;
vert[i].edgeptr = NULL;
}
for(i=0;i<vertexno;i++)
for(j=0;j<vertexno;j++)
if(matrix[i][j] > 0)
vert[i].edgeptr = insert_vertex(j,vert[i].edgeptr);
}
void dfs(int index,int *dist,struct Vertex vert[size])
{
struct Edge *link;
vert[index].visit = T;
vert[index].path_length = *dist;
*dist += 1;
for(link = vert[index].edgeptr;link;link = link->next)
if(vert[link->terminal].visit == F)
dfs(link->terminal,dist,vert);
}
void input(int number,int a[size][size])
{
int i,j;
printf("\n Input the adjacency matrix \n");
for(i=0;i<number;i++)
{
for(j=0;j<number;j++)
{
scanf("%d",&a[i][j]);
}
printf("\n");
}
}
void output(int number,int a[size][size])
{
int i,j;
printf("\n Input the adjacency matrix \n");
for(i=0;i<number;i++)
{
for(j=0;j<number;j++)
{
printf("%d",&a[i][j]);
}
printf("\n");
}
}

void main()
{
int i;
int number,index,dist;
int a[size][size];
struct Vertex vert[size];
struct Edge *list;
clrscr();
printf("\nInput the number of vertices in the graph : ");
scanf("%d",&number);
input(number,a);
output(number,a);
table(number,a,vert);
printf("\nInput the starting vertex %d : ",number-1);
scanf("%d",&index);
dist = 0;
dfs(index,&dist,vert);
printf("\nPath length of the vertex from %c ",vert[index].info);
printf("\nVertex Length Vertex Connectivity : \n ");
for(i=0;i<number;i++)
{
printf("\n %c %d",vert[i].info,vert[i].path_length);
for(list=vert[i].edgeptr;list;list=list->next)
{
printf(" ");
putchar(list->terminal+'A');
}
}
getch();
}