51nod 1182 完美字符串

#include <iostream>
#include <cctype>
#include <cstdio>
#include <cstring>
#include <algorithm>

const int MAX = 1e5 + 5;
char arr[MAX];
int sum[150];

int main()
{
scanf("%s", arr);
int lenth = strlen(arr);
for (int i = 0; i < lenth; ++i)
{
sum[tolower(arr[i])]++;
}
std::sort(sum + 'a', sum + 'a' + 26);
int res = 0, score = 26;
for (int i = 'a' + 25; i >= 'a' && sum[i]; --i)
{
res += (sum[i] * (score--));
}
std::cout << res << std::endl;
return 0;
}