二级指针与字符串数组

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

void freestrmemory(char** arr, int length);

int main(int argc, char* argv[])
{
    char** arr = NULL;
    char tempstring[30];

    int i;
	
    for(i = 0 ; i< 6; i++)
    {
        printf("Insert data\n");
        scanf("%s",tempstring);
		
        if(arr == NULL)
        {
            arr = (char**)malloc(sizeof(char*));
        }
        else
        {
            arr = (char**)realloc(arr, sizeof(char*)*(i+1));
        }
		
        arr[i] = (char*)malloc(sizeof(char)*(strlen(tempstring) + 1));
        strcpy(arr[i], tempstring);
    }
	
    for(i = 0; i< 6; i++)
    {
        printf(" %d - %s\n", i, arr[i]);
    }
	
    freestrmemory(arr, 5);
    return 0;
}

void freestrmemory(char** arr, int length)
{
    int i;
    for( i = 0; i<=length; i++)
    {
        free(arr[i]);
    }
    free(arr);
}

Administrator@PC-20150
# String12.exe        
Insert data           
lkf                   
Insert data           
kjkjk                 
Insert data           
ddsdds                
Insert data           
d                     
Insert data           
sdsd                  
Insert data           
dsd                   
 0 - lkf              
 1 - kjkjk            
 2 - ddsdds           
 3 - d                
 4 - sdsd             
 5 - dsd