题解 | #进制转换#

#include <iostream>
using namespace std;


int main() {

    string A;
    cin >> A;
    A = A.substr(2);
    int num{};

    auto lam = [](char a) {
        int tmp = static_cast<int>(a);
        int zero = static_cast<int>('0');
        int A = static_cast<int>('A');
        if (tmp >= A)
            return 10 + tmp - A;
        else
            return tmp - zero;
    };


    for (auto v : A) {
        num += lam(v);
        num*=16;
    }
    cout << num / 16;
}
// 64 位输出请用 printf("%lld")

题目很简单。刚刚学了lambda表达式，尝试用一下