1. The address book into a dynamic version of
the header file
#ifndef _CONTACT_H_
#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
#include<string.h>
enum Option
{
EXIT,
ADD,
SEAR,
DEL,
SHOW,
CLEAR,
SORT,
DES
};
#define MAX_NAME 20
#define MAX_TEL 11
#define MAX_ADDR 15
#define MAX_SEX 3
#define MAX_NUMPERSON 1000
#define DEFAULT_SIZE 2;
#define MAX_STR 20
typedef struct Personlnfo
{
char name[MAX_NAME];
short age;
char tele[MAX_TEL];
char addr[MAX_ADDR];
char sex[MAX_SEX];
}Personlnfo;
//通讯录
typedef struct Contact
{
//Personlnfo per[MAX_NUMPERSON];
Personlnfo *per;
int usedSize;//被使用的个数
int capticty;
}Contact;
void InitContact(Contact *pCon);
void AddContact(Contact *pCon);
int SearchContact(Contact *pCon);
void DelContact(Contact *pCon);
void ShowContact(Contact *pCon);
void ClearContact(Contact *pCon);
void DestoryContact(Contact *pCon);
#endif
contact .c file
#define _CRT_SECURE_NO_WARNINGS 1
#include"Contact.h"
void InitContact(Contact *pCon)
{
assert(pCon != NULL);
//pCon->usedSize = 0;
//对数组进行初始化
//memset(pCon->per, 0, sizeof(pCon->per));
pCon->capticty = DEFAULT_SIZE;
pCon->usedSize = 0;
pCon->per = (Personlnfo *)malloc(sizeof(Personlnfo)* pCon->capticty);
assert(pCon->per != NULL);
memset(pCon->per, 0, sizeof(Personlnfo)* pCon->capticty);
}
//添加一个人物到通讯录
static int CheckFull(Contact *pCon)
{
if (pCon->usedSize == pCon->capticty)
{
Personlnfo *ptr = (Personlnfo*)realloc(pCon->per, pCon->capticty*sizeof(Personlnfo)* 2);
if (ptr != NULL)
{
pCon->per = ptr;
pCon->capticty *= 2;
printf("增容成功\n");
return 1;
}
else
{
return 0;
}
}
return 1;
}
void AddContact(Contact *pCon)
{
/*if (pCon->usedSize == MAX_NUMPERSON)
{
printf("不好意思，通讯录满了\n");
return;
}*/
int ret = CheckFull(pCon);
if (ret == 0)
{
printf("扩容失败\n");
return;
}
printf("请输入姓名;");
scanf("%s", pCon->per[pCon->usedSize].name);
printf("请输入性别;");
scanf("%s", pCon->per[pCon->usedSize].sex);
printf("请输入年龄;");
scanf("%d", &(pCon->per[pCon->usedSize].age));
printf("请输入电话;");
scanf("%s", pCon->per[pCon->usedSize].tele);
printf("请输入地址;");
scanf("%s", pCon->per[pCon->usedSize].addr);
pCon->usedSize++;
printf("添加成功\n");
}
int SearchContact(Contact *pCon)
{
int i = 0;
char name[MAX_NAME] = { 0 };
assert(pCon != NULL);
if (pCon->usedSize == 0)
{
printf("通讯录为空");
return -1;
}
printf("请输入姓名\n");
scanf("%s", name);
for (i = 0; i < pCon->usedSize; i++)
{
if (strcmp(pCon->per[i].name, name) == 0)
return 1;
else
return -1;
}
}
void DelContact(Contact *pCon)
{
int index = SearchContact(pCon);
int i = 0;
assert(pCon != NULL);
if (index == -1)
{
printf("查无此人\n");
return;
}
for (i = index; i <pCon->usedSize - 1; i++)
{
pCon->per[i] = pCon->per[i + 1];
}
pCon->usedSize--;
printf("删除成功\n");
}
void ShowContact(Contact *pCon)
{
int i = 0;
assert(pCon != NULL);
printf("%-20s %-3s %-10s %-11s %-15s\n", "姓名", "性别", "年龄", "电话", "地址");
for (i = 0; i < pCon->usedSize; i++)
{
printf("%-20s %-3s %-10d %-11s %-15s\n", pCon->per[i].name,
pCon->per[i].sex, pCon->per[i].age, pCon->per[i].tele, pCon->per[i].addr);
}
}
void ClearContact(Contact *pCon)
{
//pCon->usedSize = 0;
InitContact(pCon);
}
void DestoryContact(Contact *pCon)
{
assert(pCon != NULL);
free(pCon->per);
pCon->per = NULL;
pCon->capticty = 0;
pCon->usedSize = 0;
}
test.c file
#define _CRT_SECURE_NO_WARNINGS 1
#include"Contact.h"
void menu()
{
printf("********1.add**********2.search*********\n");
printf("********3.del**********4.show***********\n");
printf("********5.clear********6.sort***********\n");
printf("********0.exit*********7.Destory********\n");
}
void start()
{
int input = 0;
//初始化通讯录 数组
Contact con;
InitContact(&con);
do
{
menu();
printf("请输入你的操作>>");
scanf("%d", &input);
switch (input)
{
case ADD:
AddContact(&con);
break;
case SEAR:
SearchContact(&con);
break;
case DEL:
DelContact(&con);
break;
case SHOW:
ShowContact(&con);
break;
case CLEAR:
ClearContact(&con);
break;
case DES:
DestoryContact(&con);
break;
}
} while (input);
}
int main()
{
start();
return 0;
}
2. Exercise dynamic memory opened
malloc
to apply a memory space continuously available, and returns a pointer pointing to this space.
Open success, returns a pointer pointing to open up good space, otherwise it returns a NULL pointer.
#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
//void* malloc(size_t size)
int main()
{
int arr[10] = { 0 };//连续的 栈
int*p = (int*)malloc(sizeof(int)* 10);//连续的 参数:40个字节 堆
assert(p != NULL);
/*if(p==NULL)
{
printf("%s\n", strerror(errno));
}*/
free(p);//释放所指向的动态内存 不free会内存泄漏
p = NULL;//野指针
system("pause");
return 0;
}
calloc
* function-element is open up a space for the size of num sizes, and the space is initialized to 0. Each byte
* malloc function differs only in that calloc will apply to each word space before the return address section initialized to zero.
#include<stdio.h>
#include<stdlib.h>
//void* calloc(size_t num, size_t size)
int main()
{
int*p = calloc(10, sizeof(int));
if(p==NULL)
{
printf("%s\n", strerror(errno));
}
free(p);
p = NULL;
return 0;
}
realloc
relloc memory function can open up resize dynamic, dynamic memory management allows more flexibility.
Original enough space: large expansion memory is added directly after the original memory space;
original space is not large enough: find another suitable size in contiguous space on the heap space is used, the function returns a new memory address.
#include<stdio.h>
#include<stdlib.h>
void* realloc(void* ptr, size_t size)
{
int*p =(int*) realloc(p, sizeof(int)* 10 * 2);//2倍扩容
assert(p != NULL);
free(p);
p = NULL;
return 0;
}
free function
to release dynamic memory open
* If the parameter is not dynamic ptr points to open up space, that behavior is undefined free function
* If the parameter is free NULL pointer, the function does not do anything.
