数据结构 / day02作业

1. 有若干个学校人员的信息,包括学生和教师。其中学生的数据包括：姓名、性别、职业s/S、分数。教师的数据包括:姓名、性别、职业t/T、职务。 1，定义指针指向堆区内存 2.循环输入 3.计算老师的个数 4.计算学生的平均值 5.循环输出 6·释放堆区空间

#include <string.h>
#include <stdlib.h>
#include <stdio.h>typedef union diff
{int score;char pos[20];}diff_t;typedef struct person
{char name[20];char gender;char job;diff_t score_or_pos;} person_t;                                                                                   person_t *req_mem(int n);
void input(int n, person_t *parr);
int count(char job, int n, person_t *parr);
void output(int n, person_t *parr);
person_t *free_mem(person_t *parr);
float avg(int n, person_t *parr);int main(int argc, const char *argv[])
{int n=3;//定义指针向堆区的内存person_t *parr=req_mem(n);/*//testperson_t arr_p[]={"zhang", 'f', 's', 98,"li", 'f', 't', "class teacher","wang", 'm', 't', "schoolmaster","zhao", 'f', 's', 97}*///输入input(n, parr);//计算老师个数int teachers = count('t', n, parr);putchar(10);printf("teacher count=%d\n", teachers);int students = count('s', n, parr);putchar(10);printf("students count=%d\n", students);//计算学生的平均值putchar(10);float  av=avg(n, parr);printf("students avg score=%.2lf\n", av);//输出putchar(10);output(n, parr);//释放堆区空间parr=free_mem(parr);return 0;
}person_t *req_mem(int n)
{person_t *p=(person_t*)malloc(sizeof(person_t)*n);if(NULL==p){printf("error");return NULL;}return p;}void input(int n, person_t *parr)                                                                                        
{for(int i=0; i<n; i++){printf("please input %d name:", i+1);scanf("%s", (parr+i)->name);printf("please input  %d gender:", i+1);scanf(" %c", &(parr+i)->gender);printf("please input %d job:", i+1);scanf(" %c", &(parr+i)->job);if('s'==((parr+i)->job) || 'S'==(parr+i)->job){printf("please input %d score:", i+1);scanf("%d", &(parr+i)->score_or_pos.score);}else if('t'==((parr+i)->job) || 'T'==(parr+i)->job){printf("please input %d position:", i+1);scanf("%s", (parr+i)->score_or_pos.pos);}}}int count(char job, int n, person_t *parr)
{int count_s=0;int count_t=0;for(int i=0; i<n; i++){char cj=(parr+i)->job;if(cj=='t'||cj=='T'){count_t++;}else if(cj=='s'||cj=='S'){count_s++;}}if (job=='t'||job=='T'){return count_t;}else if('s'==job||'T'==job){return count_s;}return -1;}      float avg(int n, person_t *parr)
{int sum=0;int count=0;for(int i=0; i<n; i++)                                                                                           {char cj = (parr+i)->job;if('s'==cj||'S'==cj){sum+=(parr+i)->score_or_pos.score;count++;}}if(count>0){return (float)sum*1.0/count;}else{return 0;}}void output(int n, person_t *parr)
{for(int i=0; i<n; i++){printf("No. %d person info:\n", i+1);printf("name=%s, gender=%c, job=%c, ", (parr+i)->name, (parr+i)->gender, (parr+i)->job );char cj=(parr+i)->job;if('s'==cj||'S'==cj){printf("score=%d\n", (parr+i)->score_or_pos.score);}else if('t'==cj||'T'==cj){printf("position=%s\n", (parr+i)->score_or_pos.pos);}putchar(10);}putchar(10);
}person_t *free_mem(person_t *parr)
{if(NULL==parr){return NULL;}free(parr);parr=NULL;return parr;}

please input 1 name:w
please input  1 gender:f
please input 1 job:s
please input 1 score:90
please input 2 name:a
please input  2 gender:f
please input 2 job:s
please input 2 score:92
please input 3 name:n
please input  3 gender:f
please input 3 job:t
please input 3 position:class teacherteacher count=1students count=2students avg score=91.00No. 1 person info:
name=w, gender=f, job=s, score=90No. 2 person info:
name=a, gender=f, job=s, score=92No. 3 person info:
name=n, gender=f, job=t, position=class

2. 以下结构体使用sizeof 计算大小的结果(默认4字节对齐)

struct s1
{char ch;int a;double b;char c1;};

s1-->20


0x00	ch
0x01
0x02
0x03
0x04	a
0x05
0x06
0x07
0x08	b
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x20	c1
0x21
0x22
0x23

写一个简单的宏, 交换A, B两数的值(假设两个变量都是char 或int类型)

struct s2
{char ch;int a;double b;};

s2-->16


0x00	ch
0x01
0x02
0x03
0x04	a
0x05
0x06
0x07
0x08	b
0x09
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F

struct s3
{char i;struct{char c;};char a;char b;char d;char e;char f;};

s3->12


0x00	i
0x01
0x02
0x03
0x04	c
0x05	a
0x06	b
0x07	d
0x08	e
0x09	f
0x0A
0x0B

3. 写一个简单的宏，交换两数的值(假设两个变量都是char或int类型)

#include <string.h>
#include <stdlib.h>
#include <stdio.h>#define EXCHANGE a=a+b; b=a-b; a=a-b;                                 int main(int argc, const char *argv[])
{int a=2;int b=3;printf("before exchange: a=%d, b=%d\n", a, b );EXCHANGE;printf("afterbefore exchange: a=%d, b=%d\n", a, b );return 0;
}