Binary Search implementation code example
Example 1: binary search algorithm
#include <bits/stdc++.h>
using namespace std;
int binarySearch(int arr[], int l, int h, int key){
if(l<=h){
int mid = l + (h-l)/2;
if(arr[mid] == key){
return mid;
}
else if(arr[mid] > key){
return binarySearch(arr, l, mid-1, key);
}
else if(arr[mid] < key){
return binarySearch(arr,mid+1, h, key);
}
}
return -1;
}
int main(){
int arr[] = {1,2,3,4,5,6,7,8,9,10};
int n = sizeof(arr)/sizeof(arr[0]);
int key = 7;
int result = binarySearch(arr,0,n-1,key);
(result==-1)
? cout << "Element is not found in the array" << endl
: cout << "Element is found at index " << result;
return 0;
}
Example 2: binary search iterative
import java.io.*;
class Binary_Search
{
public static void main(String[] args) throws Exception
{
Binary_Search obj = new Binary_Search();
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
System.out.println("Insert the length of the Array : ");
int n = Integer.parseInt(br.readLine());
int arr[] = new int[n];
System.out.println("Insert elements into the array : ");
for(int i=0;i<n;i++)
{
arr[i] = Integer.parseInt(br.readLine());
}
System.out.println("Enter the num which you want to Search : ");
int num = Integer.parseInt(br.readLine());
obj.logic(arr,num);
}
void logic(int arr[],int num)
{
int r = arr.length - 1;
int l = 0;
int mid;
while(l<=r)
{
mid = l + (r-l)/2;
if(arr[mid] == num)
{
System.out.println("Number found at "+mid+"th index");
break;
}
else if(arr[mid]>num)
{
r = mid - 1;
}
else
{
l = mid + 1;
}
}
}
}