C语言使用realloc函数实现通讯录源码分析

void ContactInit(Contact* ps)//初始化
{
	ps->size = 0;
	ps->capacity = 0;
	ps->data = NULL;
}

void ContactCheckCapacity(Contact* pc)//检查通讯录内存是否够用
{
	if (pc->size == pc->capacity)
	{
		int newcapacity = pc->capacity == 0 ? 4 : pc->capacity * 2;
		Cont* tmp = (Cont*)realloc(pc->data, newcapacity * sizeof(Cont) * 4);
		if (tmp == NULL)
		{
			perror("realloc");
			exit(-1);
		}
		pc->data = tmp;
		pc->capacity = newcapacity;
		printf("增容成功\n");
	}
}

void ContactDistory(Contact* pc)//释放动态开辟的空间
{
	free(pc->data);
	pc->data = NULL;
	pc->capacity = pc->size = 0;
}

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#define MAX_SIZE 1000
#define MAX_NAME 5
#define MAX_TELE 100
#define MAX_SEX 5
#define MAX_ADDRESS 50
typedef struct Contact
{
	char name[MAX_NAME];
	int age;
	char sex[MAX_SEX];
	char tele[MAX_TELE];
	char address[MAX_ADDRESS];
}Cont;
typedef struct C
{
	Cont *data;
	int size;
	int capacity;
}Contact;
void ContactInit(Contact* ps);//初始化
void ContactAdd(Contact* ps);//添加联系人
void ContactDel(Contact* ps);//删除联系人
void ContactShow(Contact* ps);//展示联系人
void ContactFind(Contact* ps);//查找联系人
void ContactSort(Contact* ps);//给联系人排序
void ContactModify(Contact* ps);//修改联系人
void ContactCheckCapacity(Contact* pc);//检查通讯录内存是否够用
void ContactDistory(Contact* pc);//释放动态开辟的空间

#include "contact.h"
void ContactInit(Contact* ps)//初始化
{
	ps->size = 0;
	ps->capacity = 0;
	ps->data = NULL;
}
void ContactCheckCapacity(Contact* pc)//检查通讯录内存是否够用
{
	if (pc->size == pc->capacity)
	{
		int newcapacity = pc->capacity == 0 ? 4 : pc->capacity * 2;
		Cont* tmp = (Cont*)realloc(pc->data, newcapacity * sizeof(Cont) * 4);
		if (tmp == NULL)
		{
			perror("realloc");
			exit(-1);
		}
		pc->data = tmp;
		pc->capacity = newcapacity;
		printf("增容成功\n");
	}
}
void ContactDistory(Contact* pc)//释放动态开辟的空间
{
	free(pc->data);
	pc->data = NULL;
	pc->capacity = pc->size = 0;
}
void ContactAdd(Contact* ps)//添加联系人
{
	assert(ps);
	ContactCheckCapacity(ps);
	//增加一个人的信息
	printf("请输入名字:>");
	scanf("%s", ps->data[ps->size].name);
	printf("请输入年龄:>");
	scanf("%d", &(ps->data[ps->size].age));
	printf("请输入性别:>");
	scanf("%s", ps->data[ps->size].sex);
	printf("请输入地址:>");
	scanf("%s", ps->data[ps->size].address);
	printf("请输入电话:>");
	scanf("%s", ps->data[ps->size].tele);
	ps->size++;
}
int FindByName(Contact* ps,const char *str)
{
	int pos = 0;
	while (pos < ps->size)
	{
		if (strcmp(ps->data[pos].name, str) == 0)
		{
			return pos;
		}
		pos++;
	}
	return -1;
}
void ContactFind(Contact* ps)//查找联系人
{
	assert(ps);
	printf("请输入要查找的联系人的姓名:");
	char na[MAX_NAME];
	scanf("%s", na);
	int ret = FindByName(ps, na);
	if (ret == -1)
	{
		printf("查无此人\n");
		return;
	}
	printf("%-20s\t%-4s\t%-5s\t%-20s\t%-12s\n", "名字", "年龄", "性别", "电话", "地址");
	printf("%-20s\t%-4d\t%-5s\t%-20s\t%-12s\n", ps->data[ret].name,
		ps->data[ret].age,
		ps->data[ret].sex,
		ps->data[ret].tele,
		ps->data[ret].address);
	return ;
}
void ContactDel(Contact* ps)//删除联系人
{
	assert(ps);
	printf("请输入要删除的联系人的姓名:");
	char na[MAX_NAME];
	scanf("%s", na);
	int ret = FindByName(ps, na);
	if (ret == -1)
	{
		printf("信息错误，列表无该联系人\n");
		return;
	}
	else
	{
		for (int i = ret; i < ps->size - 1; i++)
		{
			ps->data[i] = ps->data[i + 1];
		}
	}
	ps->size--;
	return;
}
void ContactShow(Contact* ps)//展示联系人
{
	int i = 0;
	printf("%-20s\t%-4s\t%-5s\t%-20s\t%-12s\n", "名字", "年龄", "性别", "电话", "地址");
	for (i = 0; i < ps->size; i++)
	{
		printf("%-20s\t%-4d\t%-5s\t%-20s\t%-12s\n", ps->data[i].name,
			ps->data[i].age,
			ps->data[i].sex,
			ps->data[i].tele,
			ps->data[i].address);
	}
}
int CmpByName(const void* a,const void* b)
{
	return strcmp(((Contact*)a)->data->name, ((Contact*)b)->data->name);
}
//return strcmp(((S*)a)->name, ((S*)b)->name);
void ContactSort(Contact* ps)//给联系人排序
{
	assert(ps);
	qsort(ps->data[0].name, ps->size, sizeof ps->data[0], CmpByName);
	printf("排序成功\n");
	return;
}
void ContactModify(Contact* ps)//修改联系人
{
	assert(ps);
	printf("请输入要修改的联系人的姓名:");
	char na[MAX_NAME];
	scanf("%s", na);
	int ret = FindByName(ps, na);
	if (ret == -1)
	{
		printf("查无此人，无法修改\n");
		return;
	}
	printf("请输入名字:>");
	scanf("%s", ps->data[ret].name);
	printf("请输入年龄:>");
	scanf("%d", &(ps->data[ret].age));
	printf("请输入性别:>");
	scanf("%s", ps->data[ret].sex);
	printf("请输入地址:>");
	scanf("%s", ps->data[ret].address);
	printf("请输入电话:>");
	scanf("%s", ps->data[ret].tele);
	printf("修改成功\n");
	return;
}

#include "contact.h"
void menu()
{
	printf("************************************\n");
	printf("******  1. 添加    2. 删除    ******\n");
	printf("******  3. 查找    4. 修改    ******\n");
	printf("******  5. 展示    6. 排序    ******\n");
	printf("******  7.退出                ******\n");
	printf("************************************\n");
}
enum Function
{
	ADD = 1,
	DEL,
	FIND,
	MODIFY,
	SHOW,
	SORT,
	EXIT
};
int main()
{
	int input = 0;
	Contact con;
	ContactInit(&con);
	do
	{
		menu();
		printf("请输入选项:");
		scanf("%d", &input);
		switch (input)
		{
		case ADD:
			ContactAdd(&con);
			break;
		case DEL:
			ContactDel(&con);
			break;
		case FIND:
			ContactFind(&con);
			break;
		case MODIFY:
			ContactModify(&con);
			break;
		case SHOW:
			ContactShow(&con);
			break;
		case SORT:
			ContactSort(&con);
			break;
		case EXIT:
			ContactDistory(&con);
			printf("退出\n");
			break;
		default:
			printf("输入错误，请重新出入\n");
			break;
		}
	} while (input != 7);
	return 0;
}