Simplify code by dropping support for legacy Python (#1143)

* Simplify code by dropping support for legacy Python

* sort() --> sorted()

dynamic_programming/bitmask.py

@@ -9,27 +9,26 @@ Find the total no of ways in which the tasks can be distributed.
 
 
 """
-from __future__ import print_function
 from collections import defaultdict
 
 
 class AssignmentUsingBitmask:
     def __init__(self,task_performed,total):
-        
+
         self.total_tasks = total    #total no of tasks (N)
-        
+
         # DP table will have a dimension of (2^M)*N
         # initially all values are set to -1
         self.dp = [[-1 for i in range(total+1)] for j in range(2**len(task_performed))]
-        
+
         self.task = defaultdict(list)   #stores the list of persons for each task
-        
+
         #finalmask is used to check if all persons are included by setting all bits to 1
         self.finalmask = (1<<len(task_performed)) - 1
-    
-    
+
+
     def CountWaysUtil(self,mask,taskno):
-        
+
         # if mask == self.finalmask all persons are distributed tasks, return 1
         if mask == self.finalmask:
             return 1
@@ -48,18 +47,18 @@ class AssignmentUsingBitmask:
         # now assign the tasks one by one to all possible persons and recursively assign for the remaining tasks.
         if taskno in self.task:
             for p in self.task[taskno]:
-                
+
                 # if p is already given a task
                 if mask & (1<<p):
                     continue
-                
+
                 # assign this task to p and change the mask value. And recursively assign tasks with the new mask value.
                 total_ways_util+=self.CountWaysUtil(mask|(1<<p),taskno+1)
-        
+
         # save the value.
         self.dp[mask][taskno] = total_ways_util
-        
-        return self.dp[mask][taskno] 
+
+        return self.dp[mask][taskno]
 
     def countNoOfWays(self,task_performed):
 
@@ -67,17 +66,17 @@ class AssignmentUsingBitmask:
         for i in range(len(task_performed)):
             for j in task_performed[i]:
                 self.task[j].append(i)
-        
+
         # call the function to fill the DP table, final answer is stored in dp[0][1]
         return self.CountWaysUtil(0,1)
-        
+
 
 if __name__ == '__main__':
-    
+
     total_tasks = 5    #total no of tasks (the value of N)
-    
+
     #the list of tasks that can be done by M persons.
-    task_performed = [ 
+    task_performed = [
         [ 1 , 3 , 4 ],
         [ 1 , 2 , 5 ],
         [ 3 , 4 ]