Question

In an array, we can swap the elements at any two indices in a single operation called a move. For example, if our array is a = {17, 4, 8}, we can swap a0 = 17 and a2 = 8 to get a = {8,4,17} in a single move. We want to custom-sort an array such that all of the even elements are at the beginning of the array and all of the odd elements are at the end of the array.
Complete the function moves. The function must return the minimum of the moves it takes to sort an array of integers with all even elements at earlier indexes that any odd element.

Note: the order of the elements within even or odd doesn’t matter

Sample input 4,13,10,21,20

Sample output 1

In JavaScript

function moves(a) {

//you code here

}

Answer 1

Answer:

function moves(a) {

   var left = 0;

   var right = a.length-1;

   var count = 0;

   while (left < right) {

       if(a[left] % 2 == 0) {

           left++;

           continue;

       }

       if(a[right] % 2 == 1) {

           right--;

           continue;

       }

       var temp = a[left];

       a[left] = a[right];

       a[right] = temp;

       left++;

       right--;

       count++;

   }

   return count;

}

var a = [4,13,10,21,20];

console.log('Number of moves: ' + moves(a));

console.log('Sorted array: ' + a);

Explanation: