【PAT】1028.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 (≤105) 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 9
Sample Output 3:
000002 James 9
000001 Zoe 60
000007 James 85
000010 Amy 90
题解
根据C的值是1还是2还是3，对相应的列排序。第一列（学号）升序，第二列（姓名）不降序，第三列（成绩）不降序。注：姓名或者成绩相同时根据学号升序排序。
import java.util.*;public class Solution2 {//学生结构体public static class Student {int id;String name;int grade;Student(int id, String name, int grade) {this.id = id;this.name = name;this.grade = grade;}}public static void main(String[] args) {List<Student> Stulist = new ArrayList<>();int N, C;Scanner in = new Scanner(System.in);N = in.nextInt();C = in.nextInt();//输入学生信息for (int i = 0; i < N; i++) {int id = in.nextInt();String name = in.next();int grade = in.nextInt();Stulist.add(new Student(id, name, grade));}//根据C 的三种不同排序方法if (C == 1) {sort(1, Stulist);}else if (C == 2) {sort(2, Stulist);}else {sort(3, Stulist);}//输出排序后的的Listfor (int i = 0; i < N; i++) {Student stu = Stulist.get(i);//按格式输出System.out.printf("%06d %s %d", stu.id, stu.name, stu.grade);System.out.println();}}public static void sort(int C, List<Student> list) {if (C == 1) {Collections.sort(list, new comparator1());}else if (C == 2) {Collections.sort(list, new comparator2());}else {Collections.sort(list, new comparator3());}}//return 1:交换位置//return -1:不交换位置// return o1-o2:升序排列public static class comparator1 implements Comparator<Student> {@Overridepublic int compare(Student o1, Student o2) {return (o1.id - o2.id) <= 0 ? -1 : 1;}}public static class comparator2 implements Comparator<Student> {@Overridepublic int compare(Student o1, Student o2) {if (o1.name.equals(o2.name)) {return (o1.id - o2.id) <= 0 ? -1 : 1;}return o1.name.compareTo(o2.name);}}public static class comparator3 implements Comparator<Student> {@Overridepublic int compare(Student o1, Student o2) {if (o1.grade == o2.grade) {return (o1.id - o2.id) <= 0 ? -1 : 1;}return (o1.grade - o2.grade <= 0) ? -1 : 1;}}
}
结果
| 测试点 | 提示 | 内存(KB) | 用时(ms) | 结果 | 得分 | |
| 0 | 17168 | 115 | 答案正确 | 5 / 5 | ||
| 1 | 16476 | 118 | 答案正确 | 5 / 5 | ||
| 2 | 16564 | 118 | 答案正确 | 5 / 5 | ||
| 3 | 16972 | 118 | 答案正确 | 2 / 2 | ||
| 4 | 16916 | 113 | 答案正确 | 2 / 2 | ||
| 5 | 16744 | 116 | 答案正确 | 2 / 2 | ||
| 6 | 51104 | 400 | 运行超时 | 0 / 4 |
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