# Large to Small Sorting Algorithm of already sorted array in JavaScript

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Suppose we have an array of integers that is already sorted in the increasing order. We are required to write a JavaScript function that without using the inbuilt Array.prototype.sort() method sorts the array like the following −

• First number should be the maximum

• Second number should be the minimum

• Third number should be the 2nd maximum

• Fourth number should be the 2nd minimum

• And so on.

For example −

If the input array is −

const arr = [1, 2, 3, 4, 5, 6];

Then the output should be −

const output = [ 6, 1, 5, 2, 4, 3 ];

## Example

Following is the code −

const arr = [1, 2, 3, 4, 5, 6];
const alternativeSort = (arr = []) => {
const res = [];
let left = 0;
let right = arr.length - 1;
while (res.length < arr.length) {
res.push(arr[right]);
if (left !== right) {
res.push(arr[left]);
}
left++;
right--;
};
return res;
};
console.log(alternativeSort(arr));

## Output

Following is the console output −

[ 6, 1, 5, 2, 4, 3 ]
Updated on 20-Jan-2021 07:03:28