c++ 16转10 code use stdhex 需要手动输入

以下是一个将16进制数转换为10进制数的C++代码，使用了std::hex。

#include #include

int main() { std::string hexStr; std::cout << "Enter a hexadecimal number: "; std::cin >> hexStr;

int decimalNum = 0;
for (char& c : hexStr) {
    if (c >= '0' && c <= '9') {
        decimalNum = decimalNum * 16 + (c - '0');
    }
    else if (c >= 'a' && c <= 'f') {
        decimalNum = decimalNum * 16 + (c - 'a' + 10);
    }
    else if (c >= 'A' && c <= 'F') {
        decimalNum = decimalNum * 16 + (c - 'A' + 10);
    }
    else {
        std::cout << "Invalid hexadecimal number!" << std::endl;
        return 0;
    }
}

std::cout << "The decimal equivalent of " << hexStr << " is " << std::hex << decimalNum << std::endl;

return 0;