max_consecutive_ones.java

/*
Given a binary array, binary means array's element will be 0 or 1.
find the maximum number of consecutive 1's in this array.
*/

import java.util.Scanner;
import java.lang.*;


public class MaxConsecutiveOnes
{
   
   static int get_max_consecutive_ones(int ar[] , int N)
   {
       int max_consecutive_ones = 0 , count_1 = 0;
       for(int i = 0; i < N; i++)
       {
            if(ar[i] == 1)
            {
               count_1++;
               //here we will keep the maximum value of consecutive 1's
               if(count_1 > max_consecutive_ones)
               {
                   max_consecutive_ones = count_1;
               }
            }
            else if(ar[i] == 0)
            {
               count_1 = 0;
            //as array's element is zero (0) we will set count_1 as zero 
            }
       }
       return max_consecutive_ones;
   }
	
   public static void main(String args[])  
   {
	Scanner scan = new Scanner(System.in);
	System.out.print("Enter the size of array \n");
	int number = scan.nextInt();
		
	int[] ar = new int[number];
	System.out.println("Enter array elements \n"); 
	for(int i = 0; i < number; i++)
	{
           ar[i] = scan.nextInt();
	}
	scan.close();
	int max_consecutive_ones = get_max_consecutive_ones(ar , number);
        System.out.print("Maximum Consecutive Ones in this array is : ");
        System.out.println(max_consecutive_ones);
		
	}
}

/*
Standard Input and Output

Enter the size of the array :
6
Enter array elements :
1 1 0 1 1 1

Maximum Consecutive Ones in this array is : 3

Time Complexity : O( N )
Space Complexity : O( 1 )

*/