Nodejs String Swap swap(l,r)

Method Source Code

var pers=[];//from w w  w  .j  a v a  2  s  .  c  o m
function permute(s,l,r){
  if(l==r) pers.push(s);
  else {
    for(var i=l;i<=r;i++) {
      s=s.swap(l,i);
      permute(s,l+1,r);
      s=s.swap(l,i);
    }
  }
}
String.prototype.swap=function(l,r) {
  return this.split('').map((a,i)=>i==l?this[r]:i==r?this[l]:a).join('');
}
permute('abc',0,2);
console.log(pers);

Related

1. swap(a, b)

   String.prototype.swap = function(a, b) {
       var array = this.split('');
       var tmp = array[a];
       array[a] = array[b];
       array[b] = tmp;
       return array.join('');
   function permutation(str, start) {
       if (start == str.length - 1) {
   ...
   

2. swapLetters(index)

   String.prototype.swapLetters = function(index) {
       var words = this.split("");
       var firstLetter = words[index];
       var lastLetter = words[words.length - 1 - index];
       var temp = firstLetter;
       words[index] = lastLetter;
       words[words.length -1 - index] = temp;
       return words.join("");
   };
   ...
   

3. swap_chars(i,j)

   String.prototype.swap_chars = function(i,j) {
       var array_string = this.split("");
       tmp = array_string[i];
       array_string[i] = array_string[j];
       array_string[j] = tmp;
       return array_string.join("");
   };
   

4. swap_substr(i)

   String.prototype.swap_substr = function(i) {
       return this.substr(0, i) + this.substr(i).split("").reverse().join("");
   };