Nodejs Array Swap swap(indexA, indexB)

Method Source Code

export default function stringPermutation(string) {
  let permutations = []/*ww w  . j  a  va 2s. c  om*/
  function recursivePermutations(array, index) {
    if(index === array.length) {
      permutations.push(array.join(''))
      return
    }
    for (let i = index; i < array.length; i++) {
      let copy = array.slice(0)
      copy.swap(index, i)
      recursivePermutations(copy, index+1)
    }
    return
  }
  recursivePermutations(string.split(''), 0)
  return permutations
}

Array.prototype.swap = function (indexA, indexB) {
  let array = this
  if (indexA === indexB) {
    return array
  }
  let temp = array[indexA]
  array[indexA] = array[indexB]
  array[indexB] = temp
  let index = indexB
  while (index !== indexA + 1) {
    temp = array[index]
    array[index] = array[index-1]
    array[index-1] = temp
    index--
  }
  return array
}

Related

1. swap(i, j)

   Array.prototype.swap = function (i, j) {
       var tmp = this[i];
       this[i] = this[j];
       this[j] = tmp;
   };
   

2. swap(i,j)

   Array.prototype.swap = function(i,j){
     var a = this;
     if(i!=j){
       a[j]^=a[i];
       a[i]^=a[j];
       a[j]^=a[i];
   

3. swap(idx1, idx2)

   function quickSort(arr){
       function partition(low, high){
           if(high - low < 2){
               return
           var pivot = arr[low]
           var wall = low
           for(var i = low; i <= high; i++){
               if(arr[i] < pivot){
   ...
   

4. swap(index1, index2)

   Array.prototype.swap = function(index1, index2) {
       var temp = this[index1];
       this[index1] = this[index2];
       this[index2] = temp;
   };
   

5. swap(index1, index2)

   Array.prototype.swap = function(index1, index2) { 
     let temp = this[index1]; 
     this[index1] = this[index2]; 
     this[index2] = temp 
   };
   

6. swap(index_A, index_B)

   Array.prototype.swap = function(index_A, index_B) {
       var input = this;
       var temp = input[index_A];
       input[index_A] = input[index_B];
       input[index_B] = temp;
   

7. swap(one, two)

   Array.prototype.swap = function (one, two) {
     var tmp = this[one];
     this[one] = this[two];
     this[two] = tmp;
   function randInt (low, high) {
     return Math.floor(Math.random() * (high - low + 1)) + low;
   function randChar () {
   ...
   

8. swap(pos1, pos2)

   Array.prototype.swap = function(pos1, pos2) {
     var temp = this[pos1];
     this[pos1] = this[pos2];
     this[pos2] = temp;
   

9. swap(sIdx, tIdx )

   ;"use strict";
   var log=function(msg){console.log(msg);};
   var alert=function(msg){log(msg);};
   var arr = [3,6,7,5,3,6,2,9,1,5,33,-12,0,-122,-Infinity, 125, 33, 55, 77];
   Array.prototype.swap = function (sIdx, tIdx ) {
     var tmp = this[sIdx];
     this[sIdx] = this[tIdx];
     this[tIdx] = tmp; 
   Array.prototype.quickSort = function () {
     function _quickSort(arr, leftIdx, rightIdx) {
       if(leftIdx < rightIdx) {
         var pivot = arr[leftIdx],
         chkLeftIdx = leftIdx,
         chkRightIdx = rightIdx;
         while(chkLeftIdx < chkRightIdx) {
           while(arr[chkRightIdx] > pivot) {
             chkRightIdx--;
           while(chkLeftIdx < chkRightIdx && arr[chkLeftIdx] <= pivot) {
             chkLeftIdx++;
           arr.swap(chkLeftIdx, chkRightIdx);
         arr.swap(leftIdx, chkLeftIdx);
         _quickSort(arr, leftIdx, chkLeftIdx-1);
         _quickSort(arr, chkLeftIdx+1, rightIdx);
       return arr;
     return _quickSort(this, 0, this.length -1);
   };
   console.log(arr.sort());
   console.log(arr.quickSort());