C++中std::partial_sort的使用小结

#include <algorithm>

template< class RandomIt >
void partial_sort( RandomIt first, RandomIt middle, RandomIt last );

template< class RandomIt, class Compare >
void partial_sort( RandomIt first, RandomIt middle, RandomIt last, Compare comp );

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

int main() {
    std::vector<int> vec = {7, 3, 9, 1, 6, 2, 8, 5, 4};

    // 仅对前 5 个元素排序
    std::partial_sort(vec.begin(), vec.begin() + 5, vec.end());

    // 输出前 5 个排序后的元素
    std::cout << "前 5 个最小的元素: ";
    for (int i = 0; i < 5; ++i) {
        std::cout << vec[i] << " ";
    }
    std::cout << "\n";

    // 输出整个数组
    std::cout << "整个数组: ";
    for (int num : vec) {
        std::cout << num << " ";
    }
    std::cout << "\n";

    return 0;
}

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

int main() {
    std::vector<int> vec = {7, 3, 9, 1, 6, 2, 8, 5, 4};

    // 获取前 5 个最大的元素（降序）
    std::partial_sort(vec.begin(), vec.begin() + 5, vec.end(), std::greater<int>());

    // 输出前 5 个排序后的元素
    std::cout << "前 5 个最大的元素: ";
    for (int i = 0; i < 5; ++i) {
        std::cout << vec[i] << " ";
    }
    std::cout << "\n";

    return 0;
}