Description:

题目大意：给出 n 个学生的ID，name，grade。

1. C = 1，按照 ID 升序排序。
2. C = 2，按照 name 升序排序，如果名字相同，按照 ID 升序排序。
3. C = 3，按照 grade 升序排序，如果 grade 相同，按照 ID 升序排序。

解题思路:

算法标签：排序

代码:

// TSWorld
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
#include <map>
#include <stack>
#include <cmath>
#include <queue>
using namespace std;
#define LL long long
const int N = 100050;

struct Node {
	string name;
	string ID;
	int grade;
}students[N];

bool cmp1(struct Node a,struct Node b) {
	return a.ID < b.ID;
}

bool cmp2(struct Node a,struct Node b) {
	if(a.name == b.name)
		return a.ID < b.ID;
	else
		return a.name < b.name;
}

bool cmp3(struct Node a,struct Node b) {
	if(a.grade == b.grade)
		return a.ID < b.ID;
	else
		return a.grade < b.grade;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	int n = 0;
	char cmd;

	cin>>n>>cmd;

	for(int i = 1;i <= n;i++) 
		cin>>students[i].ID>>students[i].name>>students[i].grade;

	if(cmd == '1') 
		sort(students+1,students+n+1,cmp1);
	else if(cmd == '2')
		sort(students+1,students+n+1,cmp2);
	else
		sort(students+1,students+n+1,cmp3);

	for(int i = 1;i <= n;i++){
		if(i != 1)
			cout<<"\n";
		cout<<students[i].ID << " " <<students[i].name<< " " <<students[i].grade;
	}
	return 0;
}