Added “Sherlock and Anagrams” solution

Author: hevalhazalkurt

solutions/3_3_Sherlock_and_Anagrams.md

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+# The HackerRank Interview Preparation Kit
+## 3. Dictionaries and Hashmaps
+
+### 3.3. Sherlock and Anagrams
+
+#### Problem
+
+Two strings are anagrams of each other if the letters of one string can be rearranged to form the other string. Given a string, find the number of pairs of substrings of the string that are anagrams of each other.
+
+For example `s = mom`, the list of all anagrammatic pairs is `[m,m], [mo,om]` at positions [[0], [2], [[0,1], [1,2]]] recpectively.
+
+<br>
+
+**Function Description**
+
+Complete the function `sherlockAndAnagrams` in the editor below. It must return an integer that represents the number of anagrammatic pairs of substrings in `s`.
+
+`sherlockAndAnagrams` has the followint parameter(s):
+* `s` : a string
+
+<br>
+
+#### Input Format
+
+The first line contains an integer `q`, the number of queries.
+
+Each of the next `q` lines contains a string `s` to analyze.
+
+<br>
+
+#### Constraints
+
+* String `s` contains only lowercase letters € ascii[a-z].
+* 1 <= `q` <= 10
+* 2 <= `|s|` <= 100
+
+
+<br>
+
+#### Output Format
+
+For each query, return the number of unordered anagrammatic pairs.
+
+<br>
+
+**Sample Input 0**
+
+```
+2
+abba
+abcd
+```
+
+<br>
+
+**Sample Output 0**
+
+```
+4
+0
+```
+
+
+<br>
+
+**Explanation 0**
+
+
+The list of anagrammatic pairs is `[a,a]`,` [ab,ba]`, `[b,b]` and `[abb,bba]` at positions `[[0,3]]`, `[[0,1], [2,3]]`, `[[1], [2]]` and `[[0,1,2],[1,2,3]]` respectively.
+
+No anagrammatic pairs exist in the second query as no character repeats.
+
+
+<br>
+
+
+**Sample Input 1**
+
+```
+2
+ifailuhkqq
+kkkk
+```
+
+<br>
+
+**Sample Output 1**
+
+```
+3
+10
+```
+
+
+<br>
+
+**Explanation 1**
+
+
+For thw first query, we have anagram pairs `[i,i]`, `[q,q]` and `[ifa,fai]` at positions `[[0], [3]]`, `[[8],[9]]` and `[[0,1,2],[1,2,3]]` respectively.
+
+For the second query:
+
+There are 6 anagrams of the form `[k,k]` at positions `[[0],[1], [[0],[2]], [[0],[3]], [[1],[2]], [[1],[3]]]` and `[[2],[3]]`
+
+There are 3 anagrams of the form `[kk,kk]` at positions `[[0,1], [1,2]]`, `[[0,1],[2,3]]` and `[[1,2],[2,3]]`
+
+There is 1 anagram of the form `[kkk,kkk]` at positions `[[0,1,2],[1,2,3]]`
+
+
+
+<br>
+
+
+**Sample Input 2**
+
+```
+1
+cdcd
+```
+
+<br>
+
+**Sample Output 2**
+
+```
+5
+```
+
+
+<br>
+
+**Explanation 2**
+
+
+There are two anagrammatic pairs of lenght `1` : `[c,c]` and `[d,d]`
+
+There are three anagrammatic pairs of lenght `2` : `[cd,dc]`, `[cd,cd]`, `[dc,cd]` at positions `[[0,1], [1,2]]`, `[[0,1], [2,3]]`, `[[1,2],[2,3]]` respectively.
+
+
+
+<br>
+
+
+### Given Code
+
+```python
+import math
+import os
+import random
+import re
+import sys
+
+# Complete the sherlockAndAnagrams function below.
+def sherlockAndAnagrams(s):
+
+if __name__ == '__main__':
+ fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+ q = int(input())
+
+ for q_itr in range(q):
+ s = input()
+
+ result = sherlockAndAnagrams(s)
+
+ fptr.write(str(result) + '\n')
+
+ fptr.close()
+```
+
+
+## Solution
+
+```python
+import math
+import os
+import random
+import re
+import sys
+
+# Complete the sherlockAndAnagrams function below.
+def sherlockAndAnagrams(s):
+ n = len(s)
+ r = 0
+
+ for i in range(1,n):
+ d = {}
+ for j in range(n-i+1):
+ subs = "".join(sorted(s[j:j+i]))
+ if subs in d:
+ d[subs] += 1
+ else:
+ d[subs] =1
+ r += d[subs]-1
+
+ return r
+
+
+if __name__ == '__main__':
+ fptr = open(os.environ['OUTPUT_PATH'], 'w')
+
+ q = int(input())
+
+ for q_itr in range(q):
+ s = input()
+
+ result = sherlockAndAnagrams(s)
+
+ fptr.write(str(result) + '\n')
+
+ fptr.close()
+
+```