如何拆分名、中、姓，并打印为姓氏、名字首字母中间首字母c++

#include <iostream>
#include <string>

int main() {
    std::string fullName = "张三";
    std::string lastName;
    std::string firstName;

    // 拆分姓氏
    lastName = fullName.substr(0, 1);

    // 拆分名字
    int firstNameStartIndex = fullName.find_last_of(" ") + 1;
    for (int i = firstNameStartIndex; i < fullName.length(); i++) {
        if (fullName[i] != ' ') {
            firstName += fullName[i];
            break;
        }
    }

    // 打印结果
    std::cout << "姓氏: " << lastName << std::endl;
    std::cout << "名字首字母中间首字母: " << firstName[0] << std::endl;

    return 0;
}

姓氏: 张
名字首字母中间首字母: 三