动态一维数组的使用

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>

int myReset(char** p,int size,int new_size)
{
int ret = 1;
int i = 0;
int len = 0;
char* pc = NULL;
if((*p!=NULL)&&(new_size>0))
{
pc = (char*)malloc(new_size*sizeof(char));
len = (size<new_size)?size:new_size;
for(i=0;i<len;i++)
{
pc[i] = **p;
(*p)++;
}
free(*p);
*p = pc;
}
else
{
ret = 0;
}
return ret;
}

int reset(char** p,int size,int new_size)
{
int ret = 1;
char* pt = NULL;
char* temp = NULL;
char* pp = *p;
int len = 0;
int i = 0;
if((p!=NULL)&&(new_size>0))
{
pt = (char*)malloc(new_size*sizeof(char));
temp = pt;
len = (size<new_size)?size:new_size;
for(i=0;i<new_size;i++)
{
if(i<len)
{
*temp++ = *pp++;  //复制旧的的元素
}
else
{
*temp++ = i;      //剩余空间添加新的元素
}
}

free(*p);
*p = pt;
}
else
{
ret = 0;
}

return ret;
}

int main(void)
{
char* pc = (char*)malloc(6*sizeof(char));
int i = 0;
printf("pc = %x\n",pc);
for(i=0;i<6;i++)
{
pc[i] = i;
}

for(i=0;i<6;i++)
{
printf("%d\n",pc[i]);
}

reset(&pc,6,50);
// myReset(&pc,length,10);

printf("pc = %x\n",pc);

for(i=0;i<50;i++)
{
printf("%d : %d\n",i,pc[i]);
}

free(pc);
printf("-----end-----\n");
return 0;
}

#include <stdio.h>
#include <malloc.h>

int myReset(char** p,int size,int new_size)
{
int ret = 1;
int i = 0;
int len = 0;
char* pc = NULL;
char* temp = NULL;
char* pp = *p;
//    for(i=0;i<size;i++)
//    {
//        printf("%d : %d\n",i,pp[i]);
//    }
if((p!=NULL)&&(new_size>0))
{
pc = (char*)malloc(new_size*sizeof(char));
len = (size<new_size)?size:new_size;
temp = pc;
printf("pc : %p\n",pc);
printf("temp : %p\n",temp);
for(i=0;i<new_size;i++)
{
if(i<len)
{
//               pc[i] = pp[i];   //这里对是应为++之后地址移动1个字节
//                *pc++ = *pp++;  //这里不对是应为++之后地址移动4个字节
*temp++ = *pp++;  //这里对是应为++之后地址移动1个字节
}
else
{
//                pc[i] = 0;      //这里对是应为++之后地址移动1个字节
*temp++ = 0;
}
printf("temp : %p\n",temp);
}

free(*p);  //注销之前的地址
*p = pc;   //二维数组指向新的地址
}
else
{
ret = 0;
}
return ret;
}

int reset(char** p,int size,int new_size)
{
int ret = 1;
char* pt = NULL;
char* temp = NULL;
char* pp = *p;
int len = 0;
int i = 0;
if((p!=NULL)&&(new_size>0))
{
pt = (char*)malloc(new_size*sizeof(char));
temp = pt;
len = (size<new_size)?size:new_size;
for(i=0;i<len;i++)
{
*temp++ = *pp++;
}
for(i=len;i<new_size;i++)
{
*temp++ = i;
}
free(*p);
*p = pt;
}
else
{
ret = 0;
}

return ret;
}

int main(void)
{
char* pc = (char*)malloc(5*sizeof(char));
int i = 0;

printf("pc : %p\n",pc); //旧的地址

printf("initial array...\n");
for(i=0;i<5;i++)
{
pc[i] = i;
}

for(i=0;i<5;i++)
{
printf("%d\n",pc[i]);
}

//    reset(&pc,5,10);
myReset(&pc,5,10);

printf("pc : %p\n",pc);//旧的地址

for(i=0;i<10;i++)
{
printf("%d : %d\n",i,pc[i]);
}

free(pc);
printf("-----end-----\n");
return 0;
}