正在验证C++中的整数输入

int num;
std::cin >> num;

if (std::cin.fail()) {
    std::cout << "Invalid input. Please enter an integer." << std::endl;
    std::cin.clear();
    std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
    // 重新接收输入
    std::cin >> num;
}

while (num < 0) {
    std::cout << "Invalid input. Please enter a non-negative integer." << std::endl;
    std::cin >> num;
}

#include <iostream>
#include <limits>

int main() {
    int num;
    std::cout << "Please enter an integer: ";
    std::cin >> num;

    while (std::cin.fail()) {
        std::cout << "Invalid input. Please enter an integer: ";
        std::cin.clear();
        std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
        std::cin >> num;
    }

    while (num < 0) {
        std::cout << "Invalid input. Please enter a non-negative integer: ";
        std::cin >> num;
    }

    std::cout << "Valid input: " << num << std::endl;

    return 0;
}