#CF50B. Choosing Symbol Pairs(有序对的数量)
Choosing Symbol Pairs(有序对的数量)
Description
There is a given string S consisting of N symbols. Your task is to find the number of ordered pairs of integers i and j such that
1. 1 ≤ i, j ≤ N
2. S[i] = S[j], that is the i-th symbol of string S is equal to the j-th.
The single input line contains S, consisting of lowercase Latin letters and digits. It is guaranteed that string S in not empty and its length does not exceed 105.
Print a single number which represents the number of pairs i and j with the needed property. Pairs (x, y) and (y, x) should be considered different, i.e. the ordered pairs count.
Input
The single input line contains S, consisting of lowercase Latin letters and digits. It is guaranteed that string S in not empty and its length does not exceed 105.
Output
Print a single number which represents the number of pairs i and j with the needed property. Pairs (x, y) and (y, x) should be considered different, i.e. the ordered pairs count.
Samples
great10
7
aaaaaaaaaa
100