Question

#include<stdio.h>

int main() {

      /* For binary search, the array should be arranged in ascending or descending order */

      int data[] = {1,2,3,4,5,6,7,8,9,10}; ****You might change the numbers for your program also

      /* 'min' use for starting location of the array, 'max' use for end location of the array and 'mid' use for middle location of the array */

      int min = 0, max = 10, search, mid = (max + min) / 2;

      printf("Enter a number to search:\n");

      scanf("%d", &search);

      while(min <= max) {

      ****** INSERT YOUR CODE TO COMPLETE THE PROGRAM ******

      }

      if(min > max)

            printf("%d is not found!\n",search);

      return 0;

}

Looking for alternative solutions for this program code.

Answer 1

#include<stdio.h>

int main()
{

//Binary Search (Considering Ascending Order of Elements in the Array)

int data[] = {1,2,3,4,5,6,7,8,9,10};

   //min, mid and max variables to indicate starting, middle and ending index (or position) of the array respectively

int min = 0, max = 10, search, mid = (max + min) / 2;

printf("Enter a number to search:\n");
scanf("%d", &search);

while(min <= max) {
  
   //If the element is greater than mid value, then mid becomes the min    
   if(data[mid]<search)
       min=mid+1;
  
   //If element is found in the middle
   else if(data[mid]==search)
   {
       printf("%d is found at index: %d",search,mid);
       break;
}
      
       //If the element is smaller than mid, then mid becomes the max
       else
       max=mid-1;
      
   //Updating the mid position
   mid= (max+min)/2;   

}
  
  
   //If the element is not found in the array  
if(min > max)
printf("%d is not found!\n",search);

return 0;

}

Sample Outputs:

Recursive Approach:

#include<stdio.h>

//bSearch() function to perform binary search with an array, min-index, max-index, search element as parameters
int bSearch(int arr[],int min,int max,int search)
{
   //variable to store mid positon
   int mid;
  
   if(min<=max)
   {
       mid = (min+max)/2;
      
       //If the element is found at mid position, then return the positon.
       if(arr[mid]==search)
           return mid;
      
       //If the search element is less than the mid value, then max=mid-1 and call bSearch()  
       else if(search<arr[mid])
           return bSearch(arr,min,mid-1,search);
      
       //If the search element is greater than the mid value, then min=mid+1 and call bSearch()  
       else
           return bSearch(arr,mid+1,max,search);  
      
   }
  
   //If the element is not found
   return -1;
  
}

void main()
{
   int arr[]={10,20,33,45,49,65,77,81,94,101};
  
   int result,search;
  
   printf("Enter a number to search:\n");
scanf("%d", &search);
  
  
   result=bSearch(arr,0,10,search);
  
   if (result==-1)
       printf("%d is not found",search);
   else
       printf("%d is found at index: %d",search,result);
  
  
}

Sample Runs: