#include<stdio.h>
#include<time.h>
#include<stdlib.h>
#define max 20
int pos;
int binsearch (int,int[],int,int,int);
int linsearch (int,int[],int);
void main()
{
int ch=1;
double t; 
int n,i,a [max],k,op,low,high,pos; 
clock_t begin,end;
while(ch)
{
printf("\n.......MENU.......\n 1.BinarySearch \n 2.Linear search \n 3.Exit \n");
printf("\n enter your choice\n");
scanf("%d",&op);
switch(op)
{
case 1:printf("\n enter the number of elments\n"); 
scanf("%d",&n);
printf("\n enter the number of an array in the order \n");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
printf("\n enter the elements to be searched \n");
scanf("%d",&k);
low=0;
high=n-1;
begin=clock();
pos=binsearch(n,a,k,low,high);
end=clock();
if(pos==-1)
printf("\n\nUnsuccessful search");
else
printf("\n element %d is found at position %d",k,pos+1);
printf("\n Time Taken is %lf CPU1 cycles \n",(end-begin)/CLK_TCK);
break;
case 2:printf("\n enter the number of elements \n");
scanf("%d",&n);
printf("\n enter the elements of an array\n");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
printf("\n enter the element to be searched \n");
scanf("%d",&k);
begin=clock();
pos=linsearch(n,a,k);
end=clock();
if(pos==-1)
printf("\n\n Unsuccessful search");
else
printf("element %d is found at position %d",k,pos+1);
printf("\n Time taken is %lf CPU cycles \n",(end-begin)/CLK_TCK); 
break;
default:printf("Invalid choice entered \n");
exit(0);
}
printf("\n Do you wish to run again(1/0) \n");
scanf("%d",&ch);
}
}
int binsearch(int n,int a[],int k,int low,int high)
{
int mid;
delay(1000);
mid=(low+high)/2;
if(low>high)
return -1;
if(k==a[mid])
return(mid);
else
if(k<a[mid])
return binsearch(n,a,k,low,mid-1);
else
return binsearch(n,a,k,mid+1,high);
}
int linsearch(int n,int a[],int k)
{
delay(1000);
if(n<0) 
return -1;
if(k==a[n-1])
return (n-1);
else
return linsearch(n-1,a,k);
}

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}