https://leetcode.com/problems/reverse-words-in-a-string/

Reverse_Words_in_a_String2.java

//https://leetcode.com/problems/reverse-words-in-a-string/
// O(1) space v
public void reverseWords(char[] s) {
    int i=0;
    for(int j=0; j<s.length; j++){
        if(s[j]==' '){
            reverse(s, i, j-1);        
            i=j+1;
        }
    }
 
    reverse(s, i, s.length-1);
 
    reverse(s, 0, s.length-1);
}
 
public void reverse(char[] s, int i, int j){
    while(i<j){
        char temp = s[i];
        s[i]=s[j];
        s[j]=temp;
        i++;
        j--;
    }
}