// JavaScript implementation of flash sort
// Flashsort is a distribution sorting algorithm showing linear computational complexity O(n)
//
// Author: Dito Baskoro

function flash_sort(arr) 
  {
    let max = 0, min = arr[0];
    let n = arr.length;
    let m = ~~(0.45 * n);
    let l = new Array(m);
 
    for (let i = 1; i < n; ++i) {
        if (arr[i] < min) {
            min = arr[i];
        }
        if (arr[i] > arr[max]) {
            max = i;
        }
    }
 
     if (min === arr[max]) {
        return arr;
    }
 
    let c1 = (m - 1) / (arr[max] - min);
 
 
    for (let k = 0; k < m; k++) {
        l[k] = 0;
    }
    for (let j = 0; j < n; ++j) {
        k = ~~(c1 * (arr[j] - min));
        ++l[k];
    }
 
    for (let p = 1; p < m; ++p) {
        l[p] = l[p] + l[p - 1];
    }
 
    let hold = arr[max];
    arr[max] = arr[0];
    arr[0] = hold;
 
    //permutation
    let move = 0, t, flash;
    j = 0; 
    k = m - 1;
  
    while (move < (n - 1)) {
        while (j > (l[k] - 1)) {
            ++j;
            k = ~~(c1 * (arr[j] - min));
        }
        if (k < 0) break;
        flash = arr[j];
        while (j !== l[k]) {
            k = ~~(c1 * (flash - min));
            hold = arr[t = --l[k]];
            arr[t] = flash;
            flash = hold;
            ++move;
        }
    }
 
    //insertion
    for (j = 1; j < n; j++) {
        hold = arr[j];
         i = j - 1;
        while (i >= 0 && arr[i] > hold) {
            arr[i + 1] = arr[i--];
        }
        arr[i + 1] = hold;
    }
    return arr;
}

//test
const array = [3, 0, 2, 5, -1, 4, 1, -2]; 
console.log("Original Array"); 
console.log(array); 
console.log("Sorted Array"); 
console.log(flash_sort(array, 0, 5));