PAT甲级——A1028 List Sorting

Excel can sort records according to any column. Now you are supposed to imitate this function.

Input Specification:

Each input file contains one test case. For each case, the first line contains two integers N (≤) and C, where N is the number of records and C is the column that you are supposed to sort the records with. Then N lines follow, each contains a record of a student. A student's record consists of his or her distinct ID (a 6-digit number), name (a string with no more than 8 characters without space), and grade (an integer between 0 and 100, inclusive).

Output Specification:

For each test case, output the sorting result in N lines. That is, if C = 1 then the records must be sorted in increasing order according to ID's; if C = 2 then the records must be sorted in non-decreasing order according to names; and if C = 3 then the records must be sorted in non-decreasing order according to grades. If there are several students who have the same name or grade, they must be sorted according to their ID's in increasing order.

Sample Input 1:

3 1
000007 James 85
000010 Amy 90
000001 Zoe 60

Sample Output 1:

000001 Zoe 60
000007 James 85
000010 Amy 90

Sample Input 2:

4 2
000007 James 85
000010 Amy 90
000001 Zoe 60
000002 James 98

Sample Output 2:

000010 Amy 90
000002 James 98
000007 James 85
000001 Zoe 60

Sample Input 3:

4 3
000007 James 85
000010 Amy 90
000001 Zoe 60
000002 James 90

Sample Output 3:

000001 Zoe 60
000007 James 85
000002 James 90
000010 Amy 90

 #include <iostream>
 #include<string>
 #include <vector>
 #include<map>
 #include <algorithm>
 using namespace std;
 struct Node
 {
     int ID, grade;
     string name;
 };
 typedef bool(*funptr)(Node a, Node b);
 bool cmp1(Node a, Node b)
 {
     return a.ID < b.ID;
 }
 bool cmp2(Node a, Node b)
 {
     return (a.name == b.name) ? a.ID < b.ID : a.name < b.name;
 }
 bool cmp3(Node a, Node b)
 {
     return (a.grade == b.grade) ? a.ID < b.ID : a.grade < b.grade;
 }

 int main()
 {
     int N, C;
     cin >> N >> C;
     vector<Node>v;
     funptr ptr[] = { &cmp1,&cmp2,&cmp3 };
     for (int i = ; i < N; ++i)
     {
         Node node;
         cin >> node.ID >> node.name >> node.grade;
         v.push_back(node);
     }
     //使用函数指针
     //sort(v.begin(), v.end(), *(ptr[C - 1]));

     //使用普通方法
     if (C == )
         sort(v.begin(), v.end(), [](Node a, Node b) {return a.ID < b.ID; });
     else if (C == )
         sort(v.begin(), v.end(), [](Node a, Node b) {return (a.name == b.name) ? a.ID < b.ID : a.name < b.name; });
     else
         sort(v.begin(), v.end(), [](Node a, Node b) {return (a.grade == b.grade) ? a.ID < b.ID : a.grade < b.grade; });
     for (auto a : v)
         cout << a.ID << " " << a.name << " " << a.grade << endl;
     return ;
 }