How to sort an array in a single loop?

Question

So I was going through different sorting algorithms. But almost all the sorting algorithms require 2 loops to sort the array. The time complexity of Bubble sort & Insert

Answer 1

The following code is in PHP to sort an array best case possible. https://paiza.io/projects/r22X0VuHvPQ236jgkataxg

<?php
function quicksort($a){
    $n = count($a);
    $lt = [];
    $gt = [];

    if($n < 2){
       return $a;
    }else{
        $f = $a[0];
    }

    for($i = 1;$i < $n ;$i++){
        if($a[$i] > $f){
            $gt [] = $a[$i];
        }else{
            $lt [] = $a[$i];
        }
    }

    return array_merge(quicksort($lt),array($f),quicksort($gt));
}


$ar = [7,4,3,6,5,1,2];
echo "Input array => ".implode(' , ',$ar).'<br>';
$a = quicksort($ar);

echo "Output array => ".implode(' , ',$a);;

?>

Answer 2

static int[] sort(int[] arr){
        int idx = 0;
        int len = arr.length - 1;
        int counter = len;
        while(true){
            if(idx != len && arr[idx] > arr[idx+1]){
                swap(arr, idx, idx + 1);
                counter--;
            }
            idx++;
            if(counter == len && idx == len){
                break;
            }
            if(idx == len){
                idx = 0;
                counter = len;
            }
        }
        return arr;
    }


    void swap(int[] arr, int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }

Answer 3

The following code is in php. you can test the code on https://paiza.io/projects/4pAp6CuB-e9vhGIblDNCZQ.

  $a = [8,3,4,9,1];
    for($i=0;$i<count($a)-1;$i++){
        if($a[$i] > $a[$i+1]){
            $temp = $a[$i];
            $a[$i] = $a[$i+1];
            $a[$i+1] = $temp;
            $i = -1;
        }
    }
    print_r($a);

Answer 4

javascript:
function bruteForce(arr){
    for(var i=0;i<arr.length; ){
        if(arr[i+1]< arr[i]){
            var temp = arr[i];
            arr[i]=arr[i+1];
            arr[i+1] = temp;
            i--;
            if(i === -1) i=0;
        }else i++;
    }

    return  arr;
 }

alert(bruteForce([2,3,4,5,6,23,1,1]));

Copy the code and paste in URL of the browser and hit enter. If the javascript: is missed then add it.

Answer 5

Here is the code to sort array using only single loop.

var array = [100, 110, 111, 1, 3, 19, 1, 11, -10]
var i = 1

while i < array.count - 1 {
    if array[i] > array[i + 1] {
        let temp = array[i];
        array[i] = array[i + 1];
        array[i + 1] = temp;
        i = -1;
    }
    i = i + 1;
}
print(array)

Answer 6

public int find2ndLargest() {
    int[] arr = {1,3,14,25,7,20,11,30};
    int temp;

    // sort array
    for (int i=0;i<arr.length-1;i++) {
        if (arr[i]>arr[i+1]) {
            temp = arr[i];
            arr[i]=arr[i+1];
            arr[i+1]=temp;
            i=0;
        }
    }
    return arr[arr.length-2];
}