Program 112: Linear Search

Program 112:
 

#include<stdio.h>
main()
{
 int i,n,search,flag=0;
 printf("Enter size of array\n");
 scanf("%d",&n);
 int a[n];
    printf("Enter the numbers\n");
    for(i=0;i<n;i++)
    {
     scanf("%d",&a[i]);
    }
    
    printf("Enter the element to be searched\n");
    scanf("%d",&search);
    for(i=0;i<n;i++)
    {
     if(a[i]==search)
     {
      flag=1;
     
     }
    }
    
    if(flag==1)
    {
     printf("Search Successful\n");
    }
    else
    {
     printf("Search is not Successful\n");
    }
}

Explanation:

1. Declaring i,n,search,flag=0,a[n]
   • n→ To store size of array
   • i →Used as helping variable
   • search→ To store number we need to search
   • flag→ To store if search is sucessfull or not
   • a[n]→ To store all the numbers given by user from which we need to find the searching number

2. printf("Enter the numbers\n");
       for(i=0;i<n;i++)
       {
        scanf("%d",&a[i]);
       }
   
   

   To take all numbers from user and storing them in array 'a' one by one

3. printf("Enter the element to be searched\n");
       scanf("%d",&search);
   
   

   Storing the number in the search variable
   
   
4.  Main logic of program

   for(i=0;i<n;i++)
   {
      if(a[i]==search)
      {
        flag=1;
        
      }
    }

• We are iterating from 0 till n (say if n=6) as in below output and array a contains numbers of 103,406,-1000,54,32,789 and our search= -1000.
• We will iterate one by one through for loop :
• Iteration 1: i=0 and a[0]=103 and a[0]==-1000 i,e 103==-1000 is false. Then proceed to next iteration and i will be incremented by 1 
• Iteration 2: i=1 and a[1]=406 and a[1]==-1000 i,e 406==-1000 is false. Then proceed to next iteration and i will be incremented by 1 \
• Iteration 3: i=2 and a[2]=-1000 and a[2]==-1000 i,e -1000==-1000 is true. so update flag to 1 
• The same way iteration will go till i=5 and flag =1 after 3rd iteration

5. if(flag==1)
   {
     printf("Search Successful\n");
   }
   else
   {
     printf("Search is not Successful\n");
   }

• Since flag==1 which is true. "Search Successful" will be printed as output

 Output: