// project1.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<string.h>const int LENGTH=1000;//分治法
int blank_pos(char str[],int beg,int end){for(int i=beg;str[i] && i<=end;i++){if(str[i]==' ')return i;}return -1;
}
void reverse_adjacent(char str[],int beg,int end){for(int i=beg,j=end;i<j;i++,j--){char tmp=str[i];str[i]=str[j];str[j]=tmp;}
}void combine(char str[],int beg,int pos,int end){char tmp[LENGTH];//将str[pos+1..end]复制到tmp[beg..beg+end-pos-1]memcpy(&tmp[beg],&str[pos+1],sizeof(char)*(end-pos));memcpy(&tmp[beg+end-pos+1],&str[beg],sizeof(char)*(pos-beg));//str[beg+end-pos]=' 'tmp[beg+end-pos]=' ';memcpy(&str[beg],&tmp[beg],sizeof(char)*(end-beg+1));
}
//分治法
void reverse_words(char str[],int beg,int end){if(str==NULL || beg==end)return;int pos=blank_pos(str,beg,end);//空格位置if(pos!=-1 && pos>=beg && pos<=end){//存在空格reverse_words(str,pos+1,end);combine(str,beg,pos,end);}
}
//先整体反转，再每个单词反转
void reverse_words_two(char str[],int beg,int end){reverse_adjacent(str,beg,end);//整体反转//每个单词反转int i=beg;while(i<=end){int start=i,ending;while(str[i] && str[i]!=' ')i++;ending=i-1;i++;//跳过空格if(start<ending)reverse_adjacent(str,start,ending);}
}int _tmain(int argc, _TCHAR* argv[])
{char str1[LENGTH]=" banana apple orange ";char str2[LENGTH]="abcdefghij klmn ";char str3[LENGTH]=" 123456789 234 986 3433 9999";reverse_words_two(str1,0,strlen(str1)-1);reverse_words(str1,0,strlen(str1)-1);printf("After reverse,str=%s\n",str1);reverse_words_two(str2,0,strlen(str2)-1);reverse_words(str2,0,strlen(str2)-1);printf("After reverse,str=%s\n",str2);reverse_words_two(str3,0,strlen(str3)-1);reverse_words(str3,0,strlen(str3)-1);printf("After reverse,str=%s\n",str3);return 0;
}