新人请教，如何利用指针跟踪数组修改一段代码？

#include
#define N 100

int main()
{
int i, j, cnt;
char ch, end;
char sentence[N];

printf("Enter a sentence: ");
i = 0;
while (1) 
{
    ch = getchar();
    if (ch == '.' || ch == '!' || ch == '?')
        break; 
    sentence[i++] = ch;
}
end = ch; 
i--;   
printf("Reserval of sentence: ");
while (i >= 0)
{
    for (cnt = 0; (i >= 0) && (sentence[i] != ' '); i--, cnt++)
        ; 
    for (j = i + 1; cnt > 0; cnt--) 
        printf("%c", sentence[j++]);
    if (i > 0)
        printf(" ");
    i--; 
}
printf("%c\n", end);

return 0;

}

http://blog.csdn.net/yaoweijq/article/details/6031792