面试题:按单词逆转字符串(2010/10/09)

代码

#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;
}