*LeetCode-Reverse Words in a String II

首先把整个string reverse 然后每个词再reverse

或者先每个词reverse 再整个reverse 注意最后一个词要记得reverse 这也是只有一个词的coner case的情况

public class Solution {
public void reverseWords(char[] s) {
reverse( s, 0, s.length - 1);
int start = 0;
int end = 0;
for ( int i = 0; i < s.length; i ++ ){
if ( s[ i ] == ' '){
reverse ( s, start, end );
start = i + 1;
}
else
end = i;
}
reverse ( s, start, end );
}
public void reverse ( char[] s, int start, int end ){
while ( start < end ){
char c = s[ start ];
s[ start ] = s [ end ];
s[ end ] = c;
start ++;
end --;
}
}
}