PAT_A 1028 List Sorting

PAT_A 1028 List Sorting

分析

题目要求对输入的数据按照C值的不同，分别对不同关键字按规则排序。偷懒的话可以写三个cmp调用sort来实现。

C的具体规则为：

• C==1 时，按照ID递增排序
• C==2 时，按照名字的非递减序排序，若重名则按照ID的递增排序
• C==3 时，按照分数的非递减序排序，若同分则按照ID的递增排序

题目的描述

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 \(N\ (≤10^5)\) 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

鸣谢用户 wangzhj 补充数据！

AC的代码

#include<bits/stdc++.h>

using namespace std;

class Student{
    public:
    char ID[10];
    char names[10];
    int grade;
    Student(){}
    Student(char id[],char n[],int g){
        strcpy(ID,id);
        strcpy(names,n);
        grade = g;
    }
};
bool cmp0(Student a,Student b){
    return strcmp(a.ID,b.ID)<0;
}
bool cmp1(Student a,Student b){
    return strcmp(a.names,b.names)==0
        ? strcmp(a.ID,b.ID)<0
        : strcmp(a.names,b.names)<0;
}
bool cmp2(Student a,Student b){
    return a.grade == b.grade
        ? strcmp(a.ID,b.ID)<0
        : a.grade<b.grade;
}
int main(){
    int N,C,n;
    array<Student,100001> students;
    scanf("%d%d",&N,&C);
    n=N;
    while(N--){
        char id[15],names[15];
        int g;
        scanf("%s%s%d",id,names,&g);
        students[N] = Student(id,names,g);
    }
    switch(C){
        case 1:
            sort(students.begin(),students.begin()+n,cmp0);
            break;
        case 2:
            sort(students.begin(),students.begin()+n,cmp1);
            break;
        case 3:
            sort(students.begin(),students.begin()+n,cmp2);
            break;
    }
    for(int i=0;i<n;i++){
        printf("%s %s %d\n",
               students[i].ID,students[i].names,students[i].grade);
    }
    return 0;
}