题解 | 字符个数统计

#include <iostream>
#include <queue>
#include <map>
#include <set>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <iomanip>
#include <stack>
#include <numeric>
#include <ctime>
#include <string>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#include <bits/stdc++.h>
#define il inline

using namespace std;
using ll = long long;
using ull = unsigned long long;

const ll N = 1e5 + 5, mod = 998244353, inf = 2e18;

il void solve() {
    string a;
    cin >> a;
    map<char, bool>mp;
    for (auto c : a) {
        mp[c] = true;
    }
    cout << mp.size();
}

int main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    int t = 1;

    //cin >> t;

    while (t--) {

        solve();

    }

    return 0;
}