面试题42：旋转字符串

#include<iostream>
#include<string.h>

using namespace std;

void reverse(char *begin, char *end){
    if(begin == NULL || end == NULL){
        return;
    }
    while(begin < end){
        char tmp = *begin;
        *begin = *end;
        *end = tmp;
        ++begin;
        --end;
    }
}

void reverse_sentence(char *begin){
    if(begin == NULL){
        return;
    }

    //找到结尾
    char* end = begin;
    while(*end != '\0'){
        ++end;
    }
    --end;
    //旋转整个字符串
    reverse(begin, end);

    //查找空格并旋转单个单词
    end = begin;
    while(*begin != '\0'){
        if(*begin == ' '){
            ++begin;
            end = begin;
        }else if (*end == ' ' || *end == '\0'){
            reverse(begin, --end);
            begin = ++end;
        }else{
            ++end;
        }
    }
}

int main(){
    char *s = new char[100];
    cin.getline(s, 100);
    reverse_sentence(s);
    cout << s << endl;
    delete []s;

    return 0;
}