186. Reverse Words in a String II.c

/*
186. Reverse Words in a String II

Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.



The input string does not contain leading or trailing spaces and the words are always separated by a single space.



For example,
Given s = "the sky is blue",
return "blue is sky the".



Could you do it in-place without allocating extra space?


Related problem: Rotate Array
*/

voidswap(char*a, char*b) {
    charc=*a;
    *a=*b;
    *b=c;
}
voidreverse(char*s, intstart, intend, intw) {
    inti, j;
    
    for (i=start, j=end; i <= j; i++, j--) {
        swap(&s[i], &s[j]);
        if (w&&s[i] ==' ') {
            reverse(s, start, i-1, 0);
            start=i+1;
        }
        if (w&&s[j] ==' ') {
            reverse(s, j+1, end, 0);
            end=j-1;
       }
   }
    
    if (w&&start<end) reverse(s, start, end, 0);
}
voidreverseWords(char*s) {
    reverse(s, 0, strlen(s) -1, 1);
}


/*
Difficulty:Medium
Total Accepted:30.2K
Total Submissions:110.3K


Companies Microsoft Amazon Uber
Related Topics String
Similar Questions 


 Reverse Words in a String

 Rotate Array
*/