R 中 %in% 运算符的 C++ 版本

R语言中的%in%运算符是一种用于判断一个元素是否属于某个集合的便捷方式。在C++中，我们可以使用相应的代码来实现类似的功能。本文将介绍如何在C++中使用%in%运算符，并提供一些实际案例代码。

cpp
#include 
#include 
#include 
int main() {
    std::vector numbers = {1, 2, 3, 4, 5};
    int target = 3;
    auto result = std::find(numbers.begin(), numbers.end(), target);
    if (result != numbers.end()) {
        std::cout << "Target element found!" << std::endl;
    } else {
        std::cout << "Target element not found!" << std::endl;
    }
    return 0;
}

cpp
#include 
#include 
#include 
int main() {
    std::vector fruits = {"apple", "banana", "orange", "grape"};
    std::string target_fruit = "apple";
    if (std::find(fruits.begin(), fruits.end(), target_fruit) != fruits.end()) {
        std::cout << target_fruit << " is in the fruits collection." << std::endl;
    } else {
        std::cout << target_fruit << " is not in the fruits collection." << std::endl;
    }
    target_fruit = "watermelon";
    if (std::find(fruits.begin(), fruits.end(), target_fruit) != fruits.end()) {
        std::cout << target_fruit << " is in the fruits collection." << std::endl;
    } else {
        std::cout << target_fruit << " is not in the fruits collection." << std::endl;
    }
    return 0;
}