九度1023 EXCEL排序

/*********************************
 *    日期：2012-7-1
 *    作者：SJF0115
 *    题号: 九度1023
 *    题目：EXCEL排序
 *    来源：http://ac.jobdu.com/problem.php?pid=1023
 *    结果：AC
 *    题意：
 *    总结：
**********************************/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef struct Student{
	char ID[10];
	char Name[10];
    int  Grade;
}Student;

int cmpByID(const void *a,const void *b){
	struct Student *c = (Student *)a;
	struct Student *d = (Student *)b;
	return strcmp(c->ID,d->ID);
}

int cmpByName(const void *a,const void *b){
	struct Student *c = (Student *)a;
	struct Student *d = (Student *)b;
	if(!strcmp(c->Name,d->Name)){
		return strcmp(c->ID,d->ID);
	}
	else{
		return strcmp(c->Name,d->Name);
	}
}

int cmpByGrade(const void *a,const void *b){
	struct Student *c = (Student *)a;
	struct Student *d = (Student *)b;
	if(c->Grade == d->Grade){
		return strcmp(c->ID,d->ID);
	}
	else{
		return c->Grade - d->Grade;
	}
}
Student student[100001];
int main()
{
	int N,C;
	int CaseNum = 0;
	//输入重定向，输入数据将从in.txt文件中读取
	//freopen("C:\\Users\\SJF\\Desktop\\in.txt","r",stdin); 
    while(scanf("%d %d",&N,&C)!=EOF)
    {   
		int i;
		if(N == 0){
			break;
		}
		CaseNum ++;
		for(i = 0;i<N;i++){
			scanf("%s %s %d",&student[i].ID,&student[i].Name,&student[i].Grade);
		}
		if(C == 1){
			qsort(student,N,sizeof(student[0]),cmpByID);
		}
		else if(C == 2){
			qsort(student,N,sizeof(student[0]),cmpByName);
		}
		else{
			qsort(student,N,sizeof(student[0]),cmpByGrade);
		}
		printf("Case %d:\n",CaseNum);
		for(i = 0;i<N;i++){
			printf("%s %s %d\n",student[i].ID,student[i].Name,student[i].Grade);
		}
    }
    return 0;
}