【C++简明教程】Python和C++指定元素排序比较

#include<vector>
#include<iostream>
#include<algorithm>
using namespace std;

int main() {
 vector<int> a;
 cout << "sort before" << endl;
 for (int i = 0; i <10; i++){
  a.push_back(10-i);
  cout << a[i] << "  ";
 }
 cout << endl;
 cout << "sort after" << endl;
 sort(a.begin(), a.end());  // 
 for (int i = 0; i < 10; i++)
 {
  cout << a[i] << "  " ;
 }
 cout << endl;
 return 0;
}

#include<vector>
#include<iostream>
#include<algorithm>
using namespace std;

# 根据第二个元素进行排序
bool sort_by_second_val(vector<int> v1, vector<int> v2) {
 return v1[1] > v2[1];
}

int main() {
    // 模拟一个输入
 vector < vector<int>> arr;
 for (int i = 0; i < 10; i+=2)
 {
  vector<int> temp;
  temp.push_back(i);
  temp.push_back(i+1);
  arr.push_back(temp);
 }
    // 排序前：arr = [[0, 1], [2, 3], [4, 5], [6, 7],[8, 9]]
 sort(arr.begin(), arr.end(), sort_by_second_val);
    // 排序后：arr = [[8, 9], [6, 7], [4, 5], [2, 3],[0, 1]]
 return 0;
}

#include<vector>
#include<iostream>
#include<algorithm>
#include <string.h>
using namespace std;

struct Studen{
 string name;
 int age;
};

bool sort_by_age(Studen s1, Studen s2) {
 return s1.age<  s2.age;

}

int main() {
 vector<Studen> studens;  // 用来存储所有学生的信息
 Studen s1, s2, s3;   // 创建 3 个学生
 s1.name = "xx";
 s1.age = 20;
 studens.push_back(s1);

 s2.name = "yy";
 s2.age = 18;
 studens.push_back(s2);

 s3.name = "zz";
 s3.age = 10;
 studens.push_back(s3);

 sort(studens.begin(), studens.end(), sort_by_age);

 return 0;
}