使用std：：函数作为c++中的参数的selectionSort

#include <iostream>
#include <vector>
#include <algorithm>

template<typename T, typename Comparator>
void selectionSort(std::vector<T>& arr, Comparator compare) {
    for (int i = 0; i < arr.size() - 1; i++) {
        int minIndex = i;
        for (int j = i + 1; j < arr.size(); j++) {
            if (compare(arr[j], arr[minIndex])) {
                minIndex = j;
            }
        }
        std::swap(arr[i], arr[minIndex]);
    }
}

int main() {
    std::vector<int> arr = {4, 2, 7, 1, 5};
    std::cout << "Before sorting: ";
    for (const auto& num : arr) {
        std::cout << num << " ";
    }
    std::cout << std::endl;
    
    // 使用std::greater作为比较函数，按照降序排序
    selectionSort(arr, std::greater<int>());
    
    std::cout << "After sorting: ";
    for (const auto& num : arr) {
        std::cout << num << " ";
    }
    std::cout << std::endl;
    
    return 0;
}