题解 | #字符个数统计#

#include <iostream>
#include <map>
using namespace std;

int CharTypes(string s)
{
    map<char,int> hashMap;
    int ans = 0;
    for (int i = 0; i < s.length(); i++){
        if (s[i] >= 0 && s[i] <= 127)
        {
            auto it = hashMap.find(s[i]);
            if (it == hashMap.end()){
                hashMap[s[i]] = 1;
                ans++;
            }
        }
    }
    return ans;
}

int main() {
    string input;
    cin >> input;
    
    cout << CharTypes(input) <<endl; 
    return 0;
}