1028 List Sorting (25 分)

1028 List Sorting (25 分)

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 Nlines 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

 

题目大意：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。
分析：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 按照分数的不降序排序，a.score <= b.score~~~
 

#include 
#include 
#include 
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;
}