7-32 | 说反话-加强版

#include "stdio.h"
#include "string.h"

int main(){	
	char words[500001];
	int start,end,i;
    int flag=-1;
	gets(words);
	end=strlen(words)-1;
	while(end>=0){
		//如果end遇到字母，则让start向前遍历找到单词的开头
		if(words[end]==' '){
			end--;
		}else{
            if(flag==1){
                printf(" ");
            }
			start=end-1;
			while(start>=0&&words[start]!=' '){
				start--;              
			}
			for(i=start+1;i<=end;i++){
				printf("%c",words[i]);
			}
			end=start;
            flag=1;
		}
	}
	return 0;
}