题解 | #字符个数统计#

#include <bits/stdc++.h>
using namespace std;
int main ()
{
    vector<char> vch;
    char ch;  
    while(cin>>ch)
        vch.emplace_back(ch);
    int sign[128] = {0}; 
    int cnt = 0;
    for(int i = 0; i < vch.size(); i++)
    {
        while(sign[vch[i]] == 0){
            sign[vch[i]]  = vch[i];
//             cout<<sign[vch[i]];
            cnt++;
        }
    }
    cout << cnt; 
    return 0;
}