usage of algorithm

# include <iostream># include <cstdlib># include <vector># include <algorithm>      //  for_each()using namespace std;// 回调函数void current(int& v){cout << v << endl;}void print(vector<int> vec){cout << "The Elements are : " << endl;for_each(vec.begin(), vec.end(), current); // 遍历算法 遍历打印 current 回调函数}int compare(int& a, int& b){return a < b; // 从小到达 如果 A < B就可以}int main(){vector<int> v(10);for(int i=9; i>=0; i--){v[9-i] = i;}print(v);sort(v.begin(), v.end(), compare);     // 排序的算法 compare 回调函数print(v);return 0;}