day10:string permutation check in python

Author: mandliya

Diff for: README.md

@@ -7,10 +7,10 @@
 | Current Status|     Stats     |
 | :------------: | :----------: |
 | Total C++ Problems | 188 |
-| Total Python Problems | 14 |
-| Current Daily Streak| 9 |
+| Total Python Problems | 15 |
+| Current Daily Streak| 10 |
 | Last Streak | 06/20/2019 - 06/21/2019|
-| Current Streak | 06/23/2019 - 07/01/2019|
+| Current Streak | 06/23/2019 - 07/02/2019|
 
 </center>
 
@@ -84,7 +84,7 @@ Include contains single header implementation of data structures and some algori
 | :------------ | :----------: |
 | Problem 1-1 : Edition 6: Write an algorithm to determine whether a string has unique characters or not. Can we do it without using additional data structures? | [1-1-hasUniqueChars.cpp](cracking_the_coding_interview_problems/1-1-hasUniqueChars.cpp), [1-1-hasUniqueChars.py](cracking_the_coding_interview_problems/1-1-hasUniqueChars.py)|
 | Problem 1-2 : Edition 5: Reverse a string when you are a pass a null terminated C string.|[1-2-edi5-reverseString.cpp ](cracking_the_coding_interview_problems/1-2-edi5-reverseString.cpp)|
-| Problem 1-2 : Edition 6: Given two strings, determine if one is permutation of other.|[1-2-perm-strings.cpp](cracking_the_coding_interview_problems/1-2-perm-strings.cpp)|
+| Problem 1-2 : Edition 6: Given two strings, determine if one is permutation of other.|[1-2-perm-strings.cpp](cracking_the_coding_interview_problems/1-2-perm-strings.cpp), [1-2-perm-strings.py](cracking_the_coding_interview_problems/1-2-perm-strings.py)|
 | Problem 1-3 : Edition 5: Write an algorithm to remove duplicate chars from a string.|[1-3-edi5-removeDuplicates.cpp](cracking_the_coding_interview_problems/1-3-edi5-removeDuplicates.cpp)|
 | Problem 1-3 : Edition 6: URLify: Replace all the spaces in a string with '%20'. Preferebly Inplace |[1-3-URLify.cpp](cracking_the_coding_interview_problems/1-3-URLify.cpp)|
 | Problem 1-4 : Edition 6: Given a string, write a function to check if it is a permutation of a pallindrome.|[1-4-pallindrome-permutations.cpp ](cracking_the_coding_interview_problems/1-4-pallindrome-permutations.cpp)|

Diff for: cracking_the_coding_interview_problems/1-2-perm-strings.py

@@ -0,0 +1,39 @@
+"""
+Cracking the coding interview edition 6
+Given two strings, determine if one is permutation of other.
+"""
+
+from collections import Counter
+
+
+def check_permutation(str1, str2):
+    """Checks if the two strings are permutations of each other
+    Args:
+        str1 : first string
+        str2 : second string
+    Returns:
+        True if strings are permutations of each other
+    """
+    # if strings are different in size, they can't be permutation of each other.
+    if len(str1) != len(str2):
+        return False
+    
+    # count the occurance of each char of str1, and match it with str2
+    counter = Counter()
+    for c in str1:
+        counter[c] += 1
+    for c in str2:
+        if counter[c] == 0:
+            return False
+        counter[c] -= 1
+    return True
+
+
+if __name__ == "__main__":
+    str1 = 'listen'
+    str2 = 'silent'
+    print(F"'{str1}' is permutation of '{str2}' : ", check_permutation(str1, str2))
+
+    str1 = 'hello'
+    str2 = 'world'
+    print(F"'{str1}' is permutation of '{str2}' : ", check_permutation(str1, str2))