Skip to main content

Given a list of numbers with only 3 unique numbers (1, 2, 3), sort the list in O(n) time.

Given a list of numbers with only 3 unique numbers (1, 2, 3), sort the list in O(n) time.

Example

Input: [3, 3, 2, 1, 3, 2, 1]
Output: [1, 1, 2, 2, 3, 3, 3]

Challenge

Try sorting the list using constant space.

Solution

function a(l) {
  for (var el of l) {
    if (typeof l1 === 'undefined') {
      l1 = [el];
    } else if (el === l1[0]) {
      l1.push(el);
    } else if (typeof l2 === 'undefined') {
      l2 = [el];
    } else if (el === l2[0]) {
      l2.push(el);
    } else if (typeof l3 === 'undefined') {
      l3 = [el];
    } else if (el === l3[0]) {
      l3.push(el);
    }
  }

  if (l1[0] < l2[0]) {
    if (l1[0] < l3[0]) {
      if (l2[0] < l3[0]){
        var l0 = l1.concat(l2).concat(l3);
      } else {
        var l0 = l1.concat(l3).concat(l2);
      }
    } else {
      var l0 = l3.concat(l1).concat(l2);
    }
  } else {
    if(l1[0] < l3[0]) { // l2 < l1 < l3
      var l0 = l2.concat(l1).concat(l3);
    } else if(l2[0] < l3[0]) { // l2 < l3 <l1
      var l0 = l2.concat(l3).concat(l1);
    } else { // l3 < l2 < l1
      var l0 = l3.concat(l2).concat(l1);
    }
  }
  return l0
}

 console.log(a([1,2,3,2,2,3,1,1,3]));
// console.log(a([1,3,2,2,2,3,1,1,3]));
// console.log(a([2,3,1,2,2,3,1,1,3]));
// console.log(a([2,1,3,2,2,3,1,1,3]));
// console.log(a([3,2,1,2,2,3,1,1,3]));
// console.log(a([3,1,2,2,2,3,1,1,3]));

Comments

Post a Comment

Popular posts from this blog

Python - List - Append, Count, Extend, Index, Insert, Pop, Remove, Reverse, Sort

🐍 Advance List List is widely used and it's functionalities are heavily useful. Append Adds one element at the end of the list. Syntax list1.append(value) Input l1 = [1, 2, 3] l1.append(4) l1 Output [1, 2, 3, 4] append can be used to add any datatype in a list. It can even add list inside list. Caution: Append does not return anything. It just appends the list. Count .count(value) counts the number of occurrences of an element in the list. Syntax list1.count(value) Input l1 = [1, 2, 3, 4, 3] l1.count(3) Output 2 It returns 0 if the value is not found in the list. Extend .count(value) counts the number of occurrences of an element in the list. Syntax list1.extend(list) Input l1 = [1, 2, 3] l1.extend([4, 5]) Output [1, 2, 3, 4, 5] If we use append, entire list will be added to the first list like one element. Extend, i nstead of considering a list as one element, it joins the two lists one after other. Append works in the following way. Input l1 = [1, 2, 3] l1.append([4, 5]) Output...
Post a Comment
Read more

Difference between .exec() and .execPopulate() in Mongoose?

Here I answer what is the difference between .exec() and .execPopulate() in Mongoose? .exec() is used with a query while .execPopulate() is used with a document Syntax for .exec() is as follows: Model.query() . populate ( 'field' ) . exec () // returns promise . then ( function ( document ) { console . log ( document ); }); Syntax for .execPopulate() is as follows: fetchedDocument . populate ( 'field' ) . execPopulate () // returns promise . then ( function ( document ) { console . log ( document ); }); When working with individual document use .execPopulate(), for model query use .exec(). Both returns a promise. One can do without .exec() or .execPopulate() but then has to pass a callback in populate.
1 comment
Read more

Resolve: Uncaught TypeError: firebase.database is not a function

If you are getting the error: Uncaught TypeError: firebase.database is not a function Resolve it by including firebase-database.js in your html page as follows: <!-- The core Firebase JS SDK is always required and must be listed first --> <script defer src = "https://www.gstatic.com/firebasejs/6.2.4/firebase-app.js" ></script> <script defer src = "https://www.gstatic.com/firebasejs/3.1.0/firebase-database.js" ></script> That is it. Let me know if this was helpful.
Post a Comment
Read more