451. Sort characters by Frequency sorting characters by frequency

Given A string, sort it in decreasing order based on the frequency of characters.

Example 1:

Input:"Tree"Output:"Eert"Explanation:' e ' appears twice while ' R ' and ' t ' both appear once. So ' e ' must appear before both ' r ' and ' t '. Therefore "Eetr" is also a valid answer.

Example 2:

Input:"cccaaa"Output:"cccaaa"Explanation:Both ' C ' and ' a ' appear three times, so "AAACCC" is Also a valid answer. Note that "Cacaca" was incorrect, as the same characters must be together.

Example 3:

Input:"Aabb"Output:"Bbaa"Explanation:"Bbaa" is also a valid answer and "Aabb" is incorrect. Note that ' a ' and ' a ' is treated as the different characters.

given a string, sort by the frequency of the characters.

  
 

   
  

  
/**
   
  

  
 * @param {string} s
   
  

  
 * @return {string}
   
  

  
 */
   
  

  
var frequencySort = function (s) {
   
  

  
 let m = {};
   
  

  
 for (let i in s) {
   
  

  
 let c = s[i];
   
  

  
 if (m[c]) {
   
  

  
 m[c]++;
   
  

  
 } else {
   
  

  
 m[c] = 1;
   
  

  
 }
   
  

  
 }
   
  

  
 let arr = [];
   
  

  
 for (let i in m) {
   
  

  
 let d = {};
   
  

  
 d.str = i;
   
  

  
 d.time = m[i];
   
  

  
 arr.push(d);
   
  

  
 }
   
  

  
 arr.sort((a, b) => {
   
  

  
 return b.time - a.time;
   
  

  
 });
   
  

  

   
  

  
 let res = "";
   
  

  
 for (let i in arr) {
   
  

  
 let item = arr[i];
   
  

  
 res += item.str.repeat(item.time);
   
  

  
 }
   
  

  
 return res;
   
  

  
};
   
  

  

   
  

  
// let s = "Aabb";
   
  

  
// console.log(frequencySort(s));
  
 

From for notes (Wiz)

451. Sort characters by Frequency sorting characters by frequency