﻿ C exercises: Binary search - w3resource

# C Exercises: Binary search

## C Programming Searching and Sorting Algorithm: Exercise-1 with Solution

Write a C program for binary search.
Note: Binary Search : In computer science, a binary search or half-interval search algorithm finds the position of a target value within a sorted array. The binary search algorithm can be classified as a dichotomies divide-and-conquer search algorithm and executes in logarithmic time.
Given a sorted array arra[] of n elements, write a function to search a given element x in arra[].

Pictorial presentation - Binary search algorithm :

Sample Solution :

C Code :

``````#include<stdio.h>
void main()
{
int  arra[100],i,n,x,f,l,m,flag=0;
printf("Input no. of elements in  an array\n");
scanf("%d",&n);
printf("Input  %d value in ascending order\n",n);
for(i=0;i<n;i++)
scanf("%d",&arra[i]);
printf("Input  the value to be search : ");
scanf("%d",&x);
/* Binary Search  logic */
f=0;l=n-1;
while(f<=l)
{
m=(f+l)/2;
if(x==arra[m])
{
flag=1;
break;
}
else  if(x<arra[m])
l=m-1;
else
f=m+1;
}
if(flag==0)
else
printf("%d value  found at %d position\n",x,m);
}
```
```

Sample Output:

```Input  no. of elements in an array
3
Input  3 value in ascending order
15
18
20
Input  the value to be search : 15
15 value  found at 0 position
```

Flowchart:

C Programming Code Editor:

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