测评会员优惠活动进行中 · 开通 VIP,有效期内测评不限次 VIP 优惠中 · 测评不限次 立即查看

A8044. Choosing Symbol Pairs

编程题 普及/提高-

题目描述

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.

输入格式

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 $10^{5}$ .

输出格式

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.

输入输出样例

输入 #1
great10
输出 #1
7
输入 #2
aaaaaaaaaa
输出 #2
100
上一题 去做题 下一题