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題目
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 (
) and
, where
is the number of records
and is the column that you are supposed to sort the records with. Then
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 lines. That is, if
=
1 then the records must be sorted in increasing order according to ID's; if
= 2 then the records must be sorted in non-decreasing order according to
names; and if = 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
思路
應(yīng)該也是很基本的排序焰络。三種排序選項，后兩個還有二級排序符喝。也沒有什么特殊的處理闪彼，所以很簡單。
代碼
最新代碼@github协饲，歡迎交流
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct {
int ID;
char name[9];
int grade;
} Student, *pStudent;
/* increasing by ID */
int cmp1(const void *a, const void *b)
{
pStudent s1 = *(pStudent*)a, s2 = *(pStudent*)b;
return s1->ID - s2->ID;
}
/* non decreasing by name, then increasing by ID */
int cmp2(const void *a, const void *b)
{
pStudent s1 = *(pStudent*)a, s2 = *(pStudent*)b;
if(strcmp(s1->name, s2->name))
return strcmp(s1->name, s2->name);
else
return s1->ID - s2->ID;
}
/* non decreasing by grade, then increasing by ID */
int cmp3(const void *a, const void *b)
{
pStudent s1 = *(pStudent*)a, s2 = *(pStudent*)b;
if(s1->grade - s2->grade)
return s1->grade - s2->grade;
else
return s1->ID - s2->ID;
}
int main()
{
int N, C;
Student buffer[100000] = {0};
pStudent students[100000] = {0}, *s = students;
scanf("%d %d", &N, &C);
for(int i = 0; i < N; i++, s++)
{
/* use a new struct buffer */
*s = buffer + i;
scanf("%d %s %d", &(*s)->ID, (*s)->name, &(*s)->grade);
}
if(C == 1) /* increasing ID */
qsort(students, N, sizeof(pStudent), cmp1);
else if(C == 2) /* non-decreasing name */
qsort(students, N, sizeof(pStudent), cmp2);
else /* C == 3, non-decreasing grade */
qsort(students, N, sizeof(pStudent), cmp3);
for(int i = 0; i < N; i++)
printf("%06d %s %d\n", students[i]->ID,
students[i]->name,
students[i]->grade);
return 0;
}
