Sort Characters By Frequency

Author: anantkaushik

Twitter/Problem#386.py

@@ -0,0 +1,20 @@
+"""
+Given a string, sort it in decreasing order based on the frequency of characters. 
+If there are multiple possible solutions, return any of them.
+For example, given the string tweet, return tteew. eettw would also be acceptable.
+"""
+def frequencySort(s: str) -> str:
+    d1, d2 = {}, {}
+    # counter of alphabets
+    for c in s:
+        d1[c] = d1.get(c, 0) + 1
+    
+    # make count as key and alphabets as value
+    for k,v in d1.items():
+        d2[v] = d2.get(v, '') + k*v
+    
+    res = ''
+    for i in range(len(s), -1, -1):
+        if i in d2:
+            res += d2[i]
+    return res