数据结构Day03

跨函数调用

动态分配内存（malloc在#include<malloc.h> 和#include<stdlib.h>中）只能自己手动释放（free）内存

 #include<stdio.h>
 int f();
 int main(void)
 {
     int i=10;
     i=f();
     printf("i=%d\n",i);
     
     
     return 0;
     
 }
 int f()
 {
     int j=20;//函数调用完毕，j没有了，静态变量 
     return j;
 }

 #include<stdio.h>
 #include<malloc.h> 
 #include<stdlib.h>
 #include<string.h>
 struct Student
 {
     int sid;
     char name[200];
     int age;
 } ;
  struct Student*CreateStudent(void);
  void ShowStudent(struct Student*);
 int main(void)
 {
     struct Student*ps;
     ps=CreateStudent();
     ShowStudent(ps);
     return 0;
     
 }
 void ShowStudent(struct Student*pst)
  {
  printf("%d",pst->sid);
   } 
 struct Student*CreateStudent(void)
 {
     struct Student*p =(struct Student*)malloc(sizeof(struct Student));
     p->sid=99;
     strcpy(p->name,"sunkuan");
     p->age=12;
     return p;
     free(p);
 }