Quicksort Algorithm

quicksort.js

/*
  Quicksort Algorithm
*/

function quicksort(array) {
  function partition(a, start, end) {
    let i = start,
        j = end + 1; 
    
    while (true) {
      while (a[++i] < a[start]) {
        if (i == end) break;
      }
      
      while (a[--j] > a[start]) {
        if (j == start) break;
      }
      
      if (i >= j) break;
      
      let c = a[i];
      a[i] = a[j];
      a[j] = c;
    }
    
    let c = a[start];
    a[start] = a[j];
    a[j] = c;
    
    return j;
  }

  function sort(a, start, end) {
    if (start >= end) return;
    
    const j = partition(a, start, end);
    
    sort(a, start + 1, j - 1);
    sort(a, j + 1, end);
  }
  
  sort(array, 0, array.length - 1);
}

const array = [7, 5, 10, 3, 4];

quicksort(array);

console.log(array);