面试题:按单词逆转字符串(2010/10/09)

#include <iostream>
#include <utility>
using namespace std;

//先逆转整个字符串,然后再逐单词逆转
char * reveser_str(char *beg,char *end=NULL)
{
    if (end==NULL)
    {
        end=beg;
        while(*end!='\0')
        {
            ++end;
        }
        --end;
    }
    char *p=beg;
    while(p<end)
    {
        swap(*p,*end);
        ++p;
        --end;
    }
    return beg;
}
char* reveser_by_word(char *str)
{
    reveser_str(str);
    char *beg=str,*end=str;
    while(*end!='\0')
    {
        if (*end==' ')
        {
            reveser_str(beg,end-1);
            beg = end+1; 
        }
        ++end;
    }
    reveser_str(beg,end-1);
    return str;
}
int main()
{
    char str[256];
    while (cin.getline(str,sizeof(str)))
    {
        cout<<reveser_by_word(str)<<endl;
    }
    return 0;
}