description:
Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.
If the last word does not exist, return 0.
Note: A word is defined as a character sequence consists of non-space characters only.
For example,
Given s = "Hello World",
return 5
Thoughts:
首先，我们先要知道s的长度是否为0，如果为0的话直接返回0。否则的话，我们从最后面开始找到第一个不为“ ”的字符，如果找不到也直接返回0，否则的话我们计算从这个字符开始连续的不为“ ”的字符的长度。这个长度就是我们所求的值。
以下是我的java代码：
package easy;
public class LengthOfLastWord {
public int lengthOfLastWord(String s) {
int position = s.length() - 1;
if(s.isEmpty()){
return 0;
}else{
while(position >= 0){
if(s.charAt(position) == ' '){
position--;
}else{
break;
}
}
if(position == -1){
return 0;
}else{
for(int i = position;i>=0;){
if(s.charAt(i) != ' ' ){
i--;
}else{
return position-i;
}
}
}
}
return position+1;
}
public static void main(String[] args){
LengthOfLastWord l = new LengthOfLastWord();
String s =" ";
System.out.println(l.lengthOfLastWord(s));
}
}