1028 List Sorting

爱被打了一巴掌 2024-04-08 11:10 68阅读 0赞

## 1028 List Sorting ##

### 0、题目 ###

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

### 1、大致题意 ###

给表格排序，根据c的值是1还是2还是3，对相应的列排序。第一列升序，第二列不降序，第三列不降序

### 2、基本思路 ###

`sort`大法，简单题

### 3、解题过程 ###

#### 3.1 char数组比较 ####

注意，按照名称的不降序排序，因为 `strcmp` 比较的是 `ACSII码` ，所以 `A < Z` 。写`cmp函数` 的时候 `return strcmp(a.name, b.name) <= 0;` return语句返回的是true或者false的值，所以要写 <= 0 这样的形式。比较 `ACSII码` 的大小，`strcmp('a', 'z')` 返回负值，因为 `a<z` `a – z < 0`  
按照分数的不降序排序，`a.score <= b.score`

#### 3.2 AC代码 ####

#include <iostream>
    #include <algorithm>
    #include <string.h>
    using namespace std;
    const int maxn = 100001;
    struct NODE {
        
        int no, score;
        char name[10];
    }node[maxn];
    int c;
    int cmp1(NODE a, NODE b) {
        
        if(c == 1) {
        
            return a.no < b.no;
        } else if(c == 2) {
        
            if(strcmp(a.name, b.name) == 0) return a.no < b.no;
            return strcmp(a.name, b.name) <= 0;
        } else {
        
            if(a.score == b.score) return a.no < b.no;
            return a.score <= b.score;
        }
    }
    int main() {
        
        int n;
        scanf("%d%d", &n, &c);
        for(int i = 0; i < n; i++)
            scanf("%d %s %d", &node[i].no, node[i].name, &node[i].score);
        sort(node, node + n, cmp1);
        for(int i = 0; i < n; i++)
            printf("%06d %s %d\n", node[i].no, node[i].name, node[i].score);
        return 0;
    }

![在这里插入图片描述][9ab339eb9fa84d05947e83578d523004.png]

[9ab339eb9fa84d05947e83578d523004.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/08/ec064cf4b7504be3819a1bdaf2d3dee0.png