1028 List Sorting（25 分）（C++)

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 90

Sample Output 3:

000001 Zoe 60
000007 James 85
000002 James 90
000010 Amy 90

解题思路：排序问题，按照题目要求即可。

#include 
#include 
#include 
#include 
using namespace std;
typedef struct{
	char info[4][15];
}stu;
int n, k;
int cmp(stu a, stu b){
	return strcmp(a.info[k],b.info[k]) != 0 ? strcmp(a.info[k],b.info[k]) < 0 : strcmp(a.info[0],b.info[0]) < 0;
}
int main(){
	scanf("%d %d", &n, &k);
	-- k;
	vectorstudents(n);
	for(int i = 0; i < n; ++ i)
		scanf("%s %s %s",students[i].info[0], students[i].info[1], students[i].info[2]);
	sort(students.begin(), students.end(), cmp);
	for(int i = 0; i < n; ++ i)
		printf("%s %s %s\n",students[i].info[0],students[i].info[1],students[i].info[2]);
}