题解

#include <iostream>
#include <string>
#include <cctype> // for isalpha and isdigit

using namespace std;

int main() {
    string input;
    getline(cin, input); // 读取一行输入

    // 去除终止符 "$?$"
    size_t pos = input.find("$?$");
    if (pos != string::npos) {
        input = input.substr(0, pos);
    }

    int letters = 0;
    int digits = 0;
    int others = 0;

    // 遍历字符串，统计各类字符的数量
    for (char c : input) {
        if (isalpha(c)) {
            letters++;
        } else if (isdigit(c)) {
            digits++;
        } else {
            others++;
        }
    }

    // 输出结果
    cout << "Letters=" << letters << endl;
    cout << "Digits=" << digits << endl;
    cout << "Others=" << others << endl;

    return 0;
}