Count the Unique number

 

Problem Statement:

We have a sorted array and we have to count the unique number and print this.

  CODE in JavaScript: 

function countUnique(array){

if(array.length){

    let i=0;

    for(let j=1;j<array.length;j++){

            if(array[i]!=array[j]){

                i++;

                array[i]=array[j];

            }

    }

    return i+1;

}

else

    throw new Error("Array is empty");

}

const result=countUnique([1,1,2,2,2,3,4,5,5,6,7,7,7]);

console.log(result);

//Output-> 7

//complexity ->  O(n)